Head Gasket Failure After 5 Hours,How Come?? - Montego Perkins Turbo.

[Guest]

Hi Lads.

Long story short.

Nothing but problems the last 2 years.

But had the block rebuilt fully.

Then reassembled.

The head has been skimmed to unfortunately almost over-skimmed (Down to a mm within tolerance)

Fitted a new payen gasket, torqued down, (Accidentally over torqued by 90Degrees.

Would this couse it to blow so soon? It seems to have blown the oil seal.

Would to much turbo PSI cause this?

Just wondering before i fit a new head gasket.

Its a Marine version of the Prima.

[E_T_V]

Is the head flat? Is the water channel divider flat and not eroded in your first pic (left most cylinder 12'O clock.

Is the block pitted on the left most cylinder second pic (under the gasket at around 7-8 O'clock). As this is usually the problem cylinder (number 4). Blows are almost always from the cylinder (4) water way.

Where and what do you think has been leaking as I can't see anything really obvious but pictures can hide all sorts!.

If oil has been leaking from the first cylinder (number 4) at the top corner of the block then this is very common and often gaskets recommend adding sealant in this area.

[Guest]

Is the head flat? Is the water channel divider flat and not eroded in your first pic (left most cylinder 12'O clock.

Is the block pitted on the left most cylinder second pic (under the gasket at around 7-8 O'clock). As this is usually the problem cylinder (number 4). Blows are almost always from the cylinder (4) water way.

Where and what do you think has been leaking as I can't see anything really obvious but pictures can hide all sorts!.

If oil has been leaking from the first cylinder (number 4) at the top corner of the block then this is very common and often gaskets recommend adding sealant in this area.

Hi mate.

Checked over the head and block.. All seems fine, no corroding (engines only done 800hrs since factory.)

Also i only had a small carpenters square as straight edge, but was flat on all the tests i done.

On piston 4, can see where its black on the block,And oil in places. This was spotless when reassembled prior to this.

Symptoms i had,

Loads of white/grey smoke on start

bubbles in coolent at high revs 3000rpm+

Also the intake gasket would air leak (Tiny bubbles), i fitted a new unipart gasket on that, and still the same?

It did look a bit messy on the block,for 5hrs use.?


Ive cleaned it all up, what passage do i put the sealant? 1 2 or 3 (see pic)
Do i do under the gasket, and above?


cheers mate

[Guest]

Heres the join of the intake manifold (Heat exchanger)

I would put 100ml of water on the join, and at 3000+rpm it would bubble,Not because of vibration, was definitely a air leak.

Would a faulty head gasket push pressure to here?

[E_T_V]

No.1 is the oil feed and when the head is lifted oil will tend to seep out and all over the block so I'd not worry unduly about a bit of oil being present.

No. 2 is the head bolt hole

No. 3 is an oil drain passage I think from the head to the sump. Check to be sure though!

If you can see no obvious issues with the block or carbon staining from escaping combustion gases then I'd have the head pressure tested just to be sure it isn't faulty.

I can't see anything obvious from the pictures I have to say. Usually the blow is very obvious.

If you compare it to this thread you'll see the corrosion and the distorted/broken fire ring on a couple of engines.
http://www.maestro.org.uk/forums/sho...eeze+regularly

If the inlet gasket is leaking then you'll usually get oily mist staining from it. Double check the boost pressure as this is really the only thing that could be amiss other than a duff gasket or warped flange.

I'd also check the heat exchanger for leaks too if it uses coolant water (as boosted air would be at a higher pressure than the coolant so could find its way into the coolant there).

[E_T_V]

Oh and I forgot to mention the block is stained from the gasket material. On the first heat cycle the gasket surface sort of goes soft and allows it to mould to the head/block surface. It can be quite difficult to remove. Scotchbrite or similar works well and shouldn't damage the block. It can also be used with care on the head too

[Guest]

Oh and I forgot to mention the block is stained from the gasket material. On the first heat cycle the gasket surface sort of goes soft and allows it to mould to the head/block surface. It can be quite difficult to remove. Scotchbrite or similar works well and shouldn't damage the block. It can also be used with care on the head too

Thanks again for your help mate.

At first the heat exchanger a crack in the exhaust.

So i bit the bullet and brought a new one "ouch"

Thought all the probs would end lol.

I will get the head pressure tested. Got a new gasket on order.

Yeah i know what you mean, no obvious blow, its so frustrating.

Going to keep below 3500rpm.

Then after a week, if ok, will test WOT. And see what happens.

Where should i put the silicine mate? 1 2 or 3?

[E_T_V]

The gasket will usually have instructions on it. If it didn't leak oil with the first gasket then it'll hopefully not leak with the second - they tended to weep oil externally not internally. It would go around number 1, but go with what the gasket recommends.

It has been a long time since I did a prima head gasket but is there a retorque procedure after 50 miles or so. I remember the head bolts are stupidly tight and need a good quality 15mm 6 sided socket to avoid rounding them off.

[Guest]

The gasket will usually have instructions on it. If it didn't leak oil with the first gasket then it'll hopefully not leak with the second - they tended to weep oil externally not internally. It would go around number 1, but go with what the gasket recommends.

It has been a long time since I did a prima head gasket but is there a retorque procedure after 50 miles or so. I remember the head bolts are stupidly tight and need a good quality 15mm 6 sided socket to avoid rounding them off.

Will have a read when it arrives..

That retourqe could be the key, as when undoing them, some "seemed" looser. Although its hard to tell.

I'll update mate, hopefully find a end to my problems.

[E_T_V]

I can't remember if there is a length spec for re-using the bolts. If so check yours as overtorquing them may have stretched them too much.

The time that mine stretched all the bolts (cam belt jumped but engine still ran!), the gasket failure wasn't obvious when looked at the block/head but it was certainly there!

[Guest]

I can't remember if there is a length spec for re-using the bolts. If so check yours as overtorquing them may have stretched them too much.

The time that mine stretched all the bolts (cam belt jumped but engine still ran!), the gasket failure wasn't obvious when looked at the block/head but it was certainly there!

I'll double check mate. I did buy a new set.

So a 90 degree overtourqe hopefully hasnt ruined them

Tis annoying, such a simple engine, yet im still striving for perfection regardless what i try lol.

[Guest]

Got my new gasket

This one says about the oil leak.

So hopefully this is where i went wrong, no sealent around the oil seal.

Seems very good quality. Around £20.

[russ10]

How is the new gasket i just fitted a payen gasket. Its throwing out coolant the red sealant is showing. I would have thought the sealant should be clamped between the head and block.