Technical Nipping up headgasket?

[dac69er]

Nipping up/retorqueing headgasket?

I know as a rule of thumb you shouldn't do this (for most engines) but what are people's opinions on doing it on the fire engine?

Reason I ask is I have a slight oily sheen around the headgasket. The engine is a fresh full rebuild and I used a decent brand headgasket. The head was torqued up correctly and the issue has only been noticeable after using the car for about 1500 miles.

I have no headgasket issues like oil/water usage, overheating or anything mixing. Just the slight external weep.

The previous engine in the car had a similar issue, but to a worse extent. I was going to try the same with that but never got round to trying it.

I know my mum had a Citroen ax years ago and that had a similar issue. I didn't know whether it's just how they are or can something be done about it?

Thanks

 

[georgeh2707]

Re: Nipping up/retorqueing headgasket?

I use that copper gasket sealing spray on head gaskets and have never had this problem with the 1.1 or 1.2 fire engine, however I noticed the same issue when I did the head gasket on my 1108 without it so I'd recommend it but it's whether you want to pull it all apart again, that was my predicament too

 

[dac69er]

Re: Nipping up/retorqueing headgasket?

Interesting. If I have to go to extent of removing I may as well attempt nipping it up as I would have nothing to lose.

Are the bolts stretch bolts? Had a search and it doesn't seem conclusive either way!? My dad suggested if they aren't stretch bolts to try undoing then retorqueing them 1 at a time

 

[andydiver]

Re: Nipping up/retorqueing headgasket?

Does the thread title sound like an euphemism or is it just me? [emoji6]

 

[portland_bill]

Re: Nipping up/retorqueing headgasket?

The head gasket is coated with an adhesive/sealant. It is/should be supplied in a sealed bag, and should be left in the bag until ready to fit. Then fit thegasket, and pop the head on without delay, torque it down as instructed. A low torque, followed by an angle turn, twice.

Once done, leave alone. If you disturb it, you break the seal.

If it is leaking, the above procedure was not followed, so replace it with new.
The head bolts are stretch bolts and may not tolersate 'nipping up'.

 

[Ralf S.]

Are you really, really sure it's leaking oil around the head gasket?

The biggest channels in the gasket (and nearest the fresh air) are for coolant, so this oil leak would have to sneak out of a smaller, more tucked away oil channel, tip-toe past the huge coolant channels without finding a way in or mixing with the coolant and then escaping down the front of your engine, even though the coolant can't use the same "loose" gasket to escape out by the same route, or to find a way into the oil.

It sounds slightly improbable to me.

Clean off the oil with a proper de-greaser and then dry it. If your missus has any talc in the house then give the motor a light dusting so that you can see where the oil is emerging from.

Then run the engine for a few minutes or drive around the block and have a look to see whether there is oil on the gasket again or if in fact it's escaping from the rocker gasket and spreading over the metal surface (as oil is designed to do).

It could also be that the oil you're seeing is residual oil, already on the block from before you fixed it, so it might not be leaking from anywhere.


But to answer the original question, nipping up the torques may or may not fix an oil leak... but usually it doesn't, since there's oil between the gasket and the head face and it's not just torque/pressure that keeps the oil out, it's also the blue sealing bead "sticking" to the metal face.

Contrary to a lot of opinion, the FIRE bolts are *not* stretch bolts. I've had them out and compared them to brand new ones (something like £8 each) and the lengths were unchanged. Stretch bolts does what they says on the tin and actually stretch, so they are longer when you take them out than when you put them in.


Ralf S.

 

[dac69er]

i am not 100% sure if it definitely originating from the headgasket at the moment until i take some bits off to investigate.

its definitely oil and it is very minimal, its not running down the block, literally a slight sheen along the joint. things like leaks rarely get better so wanted to ask the question.

i cannot find any other leaks from further up at the moment. there arent that many places it can come from that arent easily accessible.


the main area that it seems to be around is the centre front which is where the oil pressure feed channel is up to the head.

the engine was spotless when fitting and the block was painted. ive never had any issues with leaks before on other engines. as i had seen the issue before on the old engine i wondered if it was a common thing?

 

[Ralf S.]

Looks sauceh!

I would trust your own work... if you had that block, clean as it is, and you fitted a new, good quality gasket, and then torqued it down like the book says with the correct number of torques in there, then it *must* be sealing okay. On the other hand... that may be called "denial"..

I would just wipe it off and see if, when and where it comes back from. I was for a long time chasing a "rocker cover leak" only to eventually track it down to the camshaft seal.. so the oil can turn up from any random place and then just thin out and spread very thinly over the surface, miles away from where it's actually sweating from.

The good news is that some leaks just disappear (if there's just some residual oil working its way out of some nook or cranny) or they seal themselves, once crud sticks to the leak.. or they can just keep seeping mist for years and you can never track it down, it never gets worse and it never goes away. Joy!


Ralf S.

 

[dac69er]

im pretty anal when it comes to re-assembling anything
this is the first engine i have had the head and the block skimmed. i wasnt sure of the history of the engine so thought it was best to get both done for peice of mind.

only using the car for about another month or so and then i will be using my toyota again. once i have some time to strip bits off it to investigate i will see what is what and hopefully find where its coming from.

 

[blu73]

tbh if it were me i'd leave it well alone for now, drive it, see if you are losing oil and go from there, particularly as you arent intending to drive it for that long. If its losing oil you can sort it when you start driving your toyota again.

But random fact i discovered many years ago, if you look up head bolt torque specs for a cinq/sei they are not quite as tight as a mk1 p55 which is the same engine.. I've always done mine to the punto figures, not that i can remember what they are off top of my head, been too many years.

I've had a few inexplicably weep oil after HG change, nearly always at teh corner where the engine number is. Why? No idea, but whipping head off and slapping a new gasket on has always remedied. Slightly annoying but not that big a job on these really, they so simple.

 

[dac69er]

But random fact i discovered many years ago, if you look up head bolt torque specs for a cinq/sei they are not quite as tight as a mk1 p55 which is the same engine.. I've always done mine to the punto figures, not that i can remember what they are off top of my head, been too many years.

.

i cant remember what specs i used tbh. i have both a punto and cinq haynes manual. i imagine i would have used the punto specs, but perhaps i just assumed they would be the same and went with the cinq specs, i cant remember now!

i will keep an eye on it for now and have a proper investigation when it isnt my daily any more. will update if i find anything in the mean time.......

 

[dante giacosa]

I know you said a 'sheen' dac69er-

are you able to see a drop in oil level at all?

 

[dac69er]

No, it's not using any oil. If I run my finger along the joint between head and block I get a smear of oil on my finger, but not alot.

As said, it's minimal, but I like things to be 100%