Diesel Head Woes

[fastrack1966]

Having spent £250 getting my '93 Turbo Diesel through it's MOT I think the head gasket has gone. What bothers me is how - I do not thrash a car that's done over 100,000 miles, but somebody did:
I arrived back at the MOT garage as the test was finishing. I heard someone revving with their foot on the floor for minutes - yes it was my car. I know getting an old diesel through the emissions stage is hard work but is there another way than over-revving the engine for several minutes?
I had a diesel van from 1984 to 1991 and have only returned to diesel a few months ago. I see no point in labouring on with an old diesel if every time it's MOT'd I'm in for a new head gasket or worse a crack somewhere. Has anyone else had their diesel mangled like this in the good name of MOT-ing?!

Brian J

[G Force]

Hi there, I agree the MOT emissions test for diesel cars is ridiculessly harsh.

unfortunately the equipment recomended by MOT is automatic and the tester is instructed to rev the engine on the govenor until it takes a smoke reading.

All complaints should be sent to the MOT and maybe they will see the sense that a change is needed.

regards Gary

[E_T_V]

Yes I'm afraid the MOT test prescribes that some monkey wedges a brick on the accelerator to do the smoke test.

Headgaskets do tend to go on diesels around every 100k miles. But they are usually capable of doing 300k with a couple of headgaskets on the way. Ours has 200k on it and as another certain camper owner will testify it ain't too bad.

A couple of things to check are that the RPM of the govenrner is set correctly. (you could even reduce it for the MOT if required) And the MOT tester should always enquire or examine the cam belt before he berforms the test too.

[e692wtt]

Drive it at 'normal speed' but in a low gear for a couple of miles before it goes for its MoT (30mph in second in urban traffic?), including several trips 'round the block' if necessary. This will 'blow out' the last year's accumulated carbon from the exhaust pipe, as it is the disturbance of this 'accumulated carbon since the last MoT' that usually causes the Fail. Aim to run the engine at mebbe 4000 rpm if there's a rev counter...

[J199 HHG]

Turn down the max speed screw, so the car hardly moves. Maybe 2000 rpm max. They won't bust it then in the MOT. Simply readjust afterwards back to a sensible setting.

Worked for me!

[fastrack1966]

Thanks everyone.
I recall a poster that put sunflower oil in his engine somewhere! However having just changed the water pump and timing belt I've looked at the manual for the head removal and just the first bit on removing the camshaft makes me think I don't want to go through all that again.
If there's anyone around Kent/Sussex who wants the job I can drive the car over.......
Brian J

[fastrack1966]

Am I right in thinking the valves lie below the face of the head on a 2L TD? If so then can't the camshaft stay in the head during head removal and skimming? This assumes I'm leaving the valves intact too of course.

Brian J

[E_T_V]

what makes you think that the headgasket has gone? the usual first signs are highly pressurised water hoses after only a few minutes of engine running and a huge steam cloud left behind you when driving

[MGTurbo]

I've got a similar problem on my Monty TD. After prolonged heavy boost (which lets be honest, is not that often!) i'll lose some water from the expansion tank. The hoses go rock hard but the engine never indicates its getting 'that' hot. Driven normally, it's fine, no water loss and no smoke. IMO, best left. But i suspect it's the head lifting off the block that causes the symptoms due to a degree of stretch in the bolts, under heavy load this allows some compression to leak past direct into the cooling system, if left, the head *could* get cracked, but this is worse case scenerio. I had to do a water pump recently on my Monty and it wasn't the nicest of jobs, looking at it, doing a head gasket swop is actually easier! So not the end of the world. In conclusion, it the car drive fine 95% of the time and loses no water and doesn't run hot, best left. If however its losing water all the time, then it would be a good thing to get it fixed.

With regards to the head, the valves would have to be removed to be skimmed, meaning a complete strip-down and possibly re-seating the valves.

Gareth

[fastrack1966]

[B]what makes you think that the headgasket has gone? the usual first

Because a man in a yellow van said it was! No seriously.......

I have been losing water but no sign of it in the road. I've got to the stage of filling most of the cooling capacity every 20-30 miles, which is as bad as before I replaced the water pump. Definitely no leaks there.
The last two weeks the engine has given a strange shudder/jolt on turning the key. I'd switch off, re-turn and off we go. One morning after driving off at 8 am I returned to the car at 11 am, shudder/jolt and each turn of the key the symptoms got worse until I feared I had valves & pistons arguing with each other. Whilst awaiting the AA a final turn of the key convinced me the engine had seized.
AA Man checks coolant and has to practically refill the lot. Engine starts reluctantly and there's a long streak of p**s along the road from the exhaust pipe. "That's water" he says.
His theory is one or more cylinders are taking in water so badly that it is preventing the engine turning until the water is somehow displaced. I have never heard of this and would have disbelieved it but I saw it...
Mild mayo in the oil filler cap. AA Man's gas test showed nothing.

[E_T_V]

Yes sounds like it has gone. I'd get it sorted as if you haven't already you are likely to bend the con rods as water doesn't compress too well. (the reason it feels seized is because the cylinder is full of water and cannot be compressed by the piston. If you are lucky the gasket has gone between two cylinders which gives the water an escape route into another cylinder. If not you bend the con rods. I know as our Rover 600 engine died this way being driven through a deep puddle. Bent the con rod on one cylinder and the engine had to be changed to maintain its warrenty.

Time to get brave remove the head and have it skimmed, and get a new gasket I think.

[fastrack1966]

So I made a start. After struggling with a rounded 10 mm nut on the hub-type camshaft gear I now have the 4 gear nuts freed. However I'm turning the crankshaft pulley to try and lock the timing and the engine will only turn about 90 degrees either way, it then stops like its locked. I had the timing locked easily enough yesterday until the nut decided to round itself, so I unlocked the timing (belt attached!) freed the nut, which did involve some turning of the camgear, now the engine won't turn 360 degrees. The key has come out of the camgear with all my hammering does that matter?
Many thanks

Brian J

[fastrack1966]

Decided to abandon the timing to solve this, locked camshaft and injector pulley at TDC, removed belt, prepared to fit flywheel bolt as the crank turned and guess what, it still jams at about 90 degrees either direction?!
Everything is off from the head except the turbo, so I assume lifting the head will reveal all..........
I'm used to the lump of wood and mallet technique - is there an effortless alternative to get this head off anyone?

BrianJ

[BIGLAD]

Originally posted by fastrack1966
So I made a start. After struggling with a rounded 10 mm nut on the hub-type camshaft gear I now have the 4 gear nuts freed. However I'm turning the crankshaft pulley to try and lock the timing and the engine will only turn about 90 degrees either way, it then stops like its locked. I had the timing locked easily enough yesterday until the nut decided to round itself, so I unlocked the timing (belt attached!) freed the nut, which did involve some turning of the camgear, now the engine won't turn 360 degrees. The key has come out of the camgear with all my hammering does that matter?
Many thanks

Brian J
Hi,
Leave the 4 x 10mm nuts?/bolts alone, just undo the main (19 mm i think) bolt that secures the pulley and gear assembly to the cam.

[fastrack1966]

I've got the cam gear off OK now thanks, what's bugging me is the crank jamming before the engine has done even half a revolution. The crank is now detached from the timing altogether so what can be holding it? I can't lock the flywheel at TDC if it's turn is incomplete........

BrianJ

[G Force]

hi, its the pistons hitting the valves, beause you have let the cam timing move (by undoing the 4 bolts on gear)before you locked the camshaft and crank shaft.

Just remove the head and set the cam and pump timing before you refit the head.

cheers gary

[fastrack1966]

Thanks Gary. Can you stop it raining too, I've no driveway or garage!
BrianJ

[fastrack1966]

Got the nearside end of the head loose but the offside is problematic: The cambelt inside cover has to be loosened, is the 10mm bolt towards the front of the car near cam cover front end the only bolt to undo? I've a feeling there may be a lovely inaccessible bolt to the rear of the cover fixing it to the head? Does the thermostat have to come completely away?
I assume the turbo and exhaust manifold all lift away attached to the head. Although the books describe undoing various bits of the upper exhaust and the turbo they are unclear as to what ends up on the bench.

When this thing is off I think I'll run a poll for the worst part to remove in getting this head off - my vote goes to the elbow stiffener. Access forbids the use of a socket and you can't use a long arm on the ring spanner your'e so near the ground. The axle stands are as high as my jacks go,

BrianJ

[G Force]

hi, Cant just remember how many bolts secure the inside cam cover, more than one i think. Thermostat housing stays on. if you are leaving the turbo on the head you will have to disconnect the exhaust front pipe, turbo oil feed and oil return pipes.

hope its stopped raining! regards gary

[BIGLAD]

Hi,
I'm pretty sure that once you've got the Cam pulley off there is 1 (possibly 2) 8mm headed bolts that pass thru the cover into the head? (the cover has brass inserts to avoid over-tightening?)

[J199 HHG]

I always left the exhaust manifold attached to the exhaust. Saves undoing all the oil plumbing which is a right pain.

It is possible to remove the head without removing the cam inner cover - remove the wheel from the end of the cam, then remove the bolt(s) holding the cover to the head, then lift the head up and away.

I managed to get a head change down to 6 hours after some practice.

Get it skimmed and crack / pressure tested whilst it's off. They do crack - I lost two that way. Dunno why either. Apart from cruising at 90mph for hours.

[fastrack1966]

Thanks Guys
The oil return pipe was the least accessible bolt yet and only takes an open-end spanner. If anyone finds the same, unbolt it from it's extreme offside end, that means you'll have a long dangly pipe to watch when the head comes off!
Indeed there are two bolts holding the inner timing belt cover onto the head-I missed the rearward bolt,it was obscured by the timing gear.
The head is very loose now but something is still snagging seems like to the rear offside - not the oil return pipe I hope. Maybe if I put the engine back solid on it's mount it might help! Cannot resume until Monday thank goodness........

BrianJ

[BIGLAD]

There are Two Oil pipes, the Feed and the drain/return.
FOR THE RETURN/DRAIN -The best way i have found is to undo the 2 jubilee clips that hold the (oil resistant) small length of hose and slide the hose up the pipe that exits the Turbocharger. (the hose joins the Turbo and the "elbow" that is an interference/push fit into the bottom/flange of the block) This is usually awkward/hidden by the bracket that bolts from the turbo to the block. (i presume as a "steady/stiffening" idea.)Undo the (i'm pretty sure)3 bolts that secure this bracket to the block and "gently lever"/BEND it away from the block.
THE OIL FEED- undo the feed pipe from the top of the oil pump (10/11 or 13mm union- i can't remember)
There is ALSO a "P" type clip that secures this metal pipe to the block- ( this is the one people miss/forget)before it goes "up and over" into the turbo.
Then providing that you have undone every thing else the Head should lift off.You may need to guid the oil feed pipe around the (now loose) downpipe ball socket/flange.
Thanks
Biglad;)

[MGTurbo]

Why is the turbo being removed for head removal?? Once the inlet manifold is removed for access, the exhaust manifold/turbo can be levered back enough to come off the studs on the head without causing any damage. Sounds like your making alot of work for yourself.

Gareth

[MGTurbo]

Ok, just for confirmation, as my head gasket blew last night, the exhaust manifold and Turbo CAN stay in place, once everything has been removed. Took me 3 hours to do it this way. Symptoms where, no coolant loss but would start to blow it out on a hard run, and got worse recently. Heater going cold, gauge going to half-way all the time. No smoke being blown out either. Here's the evidence...

Gareth

[MGTurbo]

And this is what it should look like =

[E_T_V]

They always seem to go around number 4 pot. Must be a design problem.
Does anyone know if you can get copper gaskets for them as these are much more resilient.

[MGTurbo]

Personally, i think it's the anti-freeze that hasnt been changed on a regular basis that caused this failure. Corrosion was evident on the block and head surface where the blow occured, there was also alot of built up scale causing poor ciruclation around the head. Looks like hard water to me. But good thing is, head is fine, as is the block after a good clean, so should be good for another 150k...

Gareth

[thart]

Originally posted by J199 HHG
Turn down the max speed screw, so the car hardly moves. Maybe 2000 rpm max. They won't bust it then in the MOT. Simply readjust afterwards back to a sensible setting.

Worked for me!

That sounds like very good advice HHG. on my last MOT the smoke coming from the exhaust and turbo was grim, but instead of revving its nuts off, the tester sent me off to do my own revving on the road (3 miles of 35 mph in second, no smoke at all when I came back, he then passed it as OK. (go somewhere else if they go mad with the lead boot)

I have had slight water loss that I could not trace, even after replacing the pair of metal heater pipes in the pasenger footwell (they corrode), the cure I found was to tip a tin of Holts Radweld in the cooling system, this has worked magic, also this has a built in water lubricant and anti corrosion additive, well worth having in view of what can happen to an ally head with cheap or old antifreeze.

I have not had to put water in for best part of a year, oh I also put the new 5 year antifreeze at last change, probably cheaper in the long run.

By the way Radweld is much cheaper in Wilkinsons (WILCO) than Halfords.

PS You can see my car in the latest Monstro.

Tom

[fastrack1966]

Took time out for a while and after another half hour struggle saw what was snagging the head: the hose that enters at the bottom of the stat! Even that hose took ages to remove, the cast pipe part from the stat holding the hose that points to the wheelarch from the stat is about 35mm long, heaven knows why.
I started this thread (what seems like months ago) over the aggressive emissions test at the MOT. If anyone cares to read me in:
group=uk.rec.cars.maintenance on 20th Oct
you'll see plenty of posters virtually accusing me of being the careless party. Eventually someone posted what I wanted to hear: the MOT garage is meant to give us a noddy diesel leaflet with dire warnings over the emissions test. What leaflet?!

BrianJ

[fastrack1966]

Hi Everyone.
Thanks for all the advice in late 2003. Working out by the kerb meant a winter break was called for but now the head is skimmed all I have to do is put it all back together.
Going fine so far but the Book says when topping up oil in the turbo "spin the turbo". Regret it's all I can do but slowly push the fins round with my finger or worse with a screwdriver. Are they meant to spin? From my limited knowledge of turbo chargers the only force turning them when driving is air?! A hurricane woudldnt turn this one, yet I recall it spinning by hand back in November.

BrianJ

[MGTurbo]

Originally posted by fastrack1966
Hi Everyone.
Thanks for all the advice in late 2003. Working out by the kerb meant a winter break was called for but now the head is skimmed all I have to do is put it all back together.
Going fine so far but the Book says when topping up oil in the turbo "spin the turbo". Regret it's all I can do but slowly push the fins round with my finger or worse with a screwdriver. Are they meant to spin? From my limited knowledge of turbo chargers the only force turning them when driving is air?! A hurricane woudldnt turn this one, yet I recall it spinning by hand back in November.

BrianJ

The turbo should spin very easily with virtually no resistance at all, even with no oil on the shaft.

Gareth

[E_T_V]

yes it should spin quite freely.. I'd check for any opstructions like rags, or that missing spanner, if that is alright I'd try soaking the whole lot in oil to see if you can free things up.

[fastrack1966]

This is getting worrying.......removed the turbo unit, it was back on the car already, and split it where two halves are held by two semicircular plates and six bolts so you can see and touch both sets of fins. Gave it loads of oil and it moves a lot smoother, though "spin" is not the word.
However the problem arises when I reassemble the two clamps/six bolts. As soon as I tighten the bolts the fins/shaft seize and will only move if the bolts are loosened. I hope this is not terminal, since I cannot see the unit can be dismantled any further than I did, and the chance of finding a used unit within an hour of here are next to none,

BrianJ

[fastrack1966]

Resuming this many weeks long thread: Everything, even a nicely turning turbo, is back on the car. Timing was all set, fuel is coming out of the pipes at the injectors (before I tightened them) but no joy.
I fail to see how anyone can see bubbles in the fuel if theyre there. Should I catch it in a jar? It took ages for fuel to appear from the filter bleed, but it did eventually. Maybe I'll bleed it all again tomorrow?

BrianJ

[E_T_V]

bleeding the system can be an infuriating task. work from the fuel pump to the injector pump. Then the injector pump to the injectors. You can see fuel bubbles as a non steady stream of liquid coming out of the bleed valve. carry on pumping until no more bubbles emerge at the valve then move on to the next bit.

to do the injectors crack the injector nut open so that diesel leaks out. get someone to crank the engine until you see fuel seeping out of the nut regularly then tighten it up. with any luck it should them begin to fire on one cylinder. once you've got two cylinders going the rest will follow.

[fastrack1966]

What with this thread, the engine mount thread and the injectors thread I have to give up with great regrets. I'm going to canvas a couple of local garages tomorrow that have worked on my three Maestros in the past to see if they'll take on this nonstarter. I know some are reluctant when they know the owner (or anyone) has had their hands in there.
If anyone knows a sympathetic garage within half an hour of Hastings who'll have a go at it I can get it AA Relayed there but I would'nt want to go more than half an hour away unless I get even more desperate!

BrianJ

[E_T_V]

Before you give up It might be worth changing the fuel filter (as it took so long to bleed) and bleeding it all again thoroughly as this is most likey the problem.

[F 447]

;) Hello Fastrack, my car had the same trouble, it would not draw up any fuel, untill I took the fuel pump apart and found it was jammed inside. Don't know how though because it seemed to be running ok before I took the head off. Anyway, to be safe, I got a new firstline one from the local accessory shop ( about £20) and fitted that, gushed out in no time.

[fastrack1966]

There is a flow of fuel out of the injectors, its just being sure its all airfree. Renewed fuel filter and bled and bled, still no joy.
Booked into a local guy who worked on all my Maestros, but he got me worried straight away:
"Did I use a cheap head gasket"?! When I said the set was £35 he said that was average, but he told me the story of a diesel another guy worked on himself and then towed into the workshop. Failing all else workshop test the compression, its hopeless and blame is put on the "cheap" head gasket. Workshop does the job all over and car starts, so I'm told. Are some new gaskets so bad that diesel compression fails? Mine is made by FAI Gaskets. Is there a cheapo oneoff tool I can test compression with? I'd rather see it myself before starting the dreaded OneWayTrip, ie being towed to a garage........
BrianJ

[F 447]

Fastrack, I had the same trouble as you as to whether the fuel was bled or not. It seemed as long as you have cranked it over a few turns and let fuel out of the injectors (only undone slightly) then you are bled. Now, I did all this with mine and it still wouldn't start. So I decided the injector timing was too far out, so I advanced it and low and behold it started. Advanced some more to eliminate too much smoke and it nows runs quite well- but it is still out.
How did you time yours? Anyone know where I can get this special adapter and dial test gauge, so's I can get the timing accurate????

[J199 HHG]

You need a decent Diesel compression tester to check compression. It's far too high for a petrol tester.

Here's a thought - is the stop valve connected and does it have 12 volts on it?

I once spent ages bleeding and cranking before realising that the stop valve didn't have 12V on it (immobiliser fault). Fixed that, and away it went.

[fastrack1966]

Solenoid/Stop switch is fine, top nut & bolt pretty clean and it shows 12V.
Bit reluctant to tamper with the injector pump, I've not touched it throughout aprt from resetting the timing gear. I assume it will be set as it was when the car was a "fine runner"!

BrianJ

[E_T_V]

Just a thought as it appears that the same has happened to Tony's car but are you sure the timing isn't 180 degrees out?

Even if the head gasket was faulty I'd expect it to run on 1 or 2 cylinders. And you'd lose a whole lot of coolant and/or pressurise the cooling system.

Are the glow plugs working ok as they are a pig to start without them.

Does the engine fire at all?

[J199 HHG]

If when you crack open the injector unions and crank the engine you get a good squirt of diesel coming out then the fuelling is OK.

If you can get both timing pins in and the injector pump wheel marks are correct (I think it's B for the turbo, and A for the non-turbo), then all the timings are OK. Make sure you haven't got the injector pump 1 tooth out - it's quite easy to do that as the wheel is unstable when the marks are aligned.

If all the above checks out, then get the compression tested. It will start without working glowplugs if the compression is sufficient.

Chris.

[fastrack1966]

Thanks Guys

Gloplugs are all new, I got an offer £18 the set, he may still have some.
Yes the injector pump is a pig when it "springs" back just as the belt teeth are in the right place! I have a locking bolt on the front of the pump that holds it, but you still need a mirror to see the B mark. So I got a local guy to do the timing for a tenner. The camgear was definitely on B which is turbo.

BrianJ

[BIGLAD]

Originally posted by fastrack1966
Thanks Guys

Gloplugs are all new, I got an offer £18 the set, he may still have some.
Yes the injector pump is a pig when it "springs" back just as the belt teeth are in the right place! I have a locking bolt on the front of the pump that holds it, but you still need a mirror to see the B mark. So I got a local guy to do the timing for a tenner. The camgear was definitely on B which is turbo.

BrianJ
You really need the 2 bolts in the Injector pulley.
I tried "rushing" a head gskt replacement once by only using one pin in the pump. The result- after much cranking, towing and white (unburnt diesel) smoke, i decided to re-trace my steps.
The pump timing was out (probably only "1/2" a tooth) but enough for it not to start and run.

I'm not tying to rubbish anyones above post's/help/theories,(and checking for Diesel at the injectors is a good place to start) but you will have diesel at the injector unions (even if the pump timing is out.It just won't be injected at the correct time.
With your above "answer" saying you have a locking bolt (singular?), i would be inclined to recheck all the belt timing.

Biglad.

[fastrack1966]

The locking bolt isnt the two holes in the pulley but a bolt on the front of the pump with an arrow shaped plate. Removing the plate lets you screw the bolt right home lockling the pump. Undoing the bolt a bit frees the pump and you replace the arrow-plate.
Admittedly you still have to ensure the pump is correctly positioned with the two pulley bolts first.......
Is it possible to bend a valve turning the engine with the timing two teeth out? Oops,
BrianJ

[BIGLAD]

If the timing is too far out, Valve and piston contact will happen.
Although i don't know for sure how many teeth this needs to be.
If you are turning the engine by hand then it just usually "locks up" and means you cannot turn it any further.
If the belt breaks or comes of while the engine is running at much above idle speed it usually snaps the cam in 3-4 places.
Try pinning the injector pulley with two bolts instead-its got to be worth a go? (i cant remeber if they are M6 or M8 though)
:confused:

Biglad

[fastrack1966]

At least its an epilogue and not an orbituary! At last the epic blockbuster Diesel Head Woes reaches a successful conclusion, I'm driving my car! It seems fitting that we've just passed 1001 views of this thread. Relayed it to a garage who detected the nbr 1 injector wasnt properly sealed. No idea why or how they cured it. From some of your posts I'm surprised she didnt at least start on 3 cylinders but c'est la vie, at least he didnt have to undo everything I had done.
I thought the smokescreen was going to take a week to clear but it vanished suddenly after a 10 mile run. Some onlookers may have felt inclined to complain but I doubt if they could see the car.
Many thanks to all who have contributed and I'm sure hundreds more have been entertained as well.

BrianJ