Possible Cylinder Head Leak AAN Engine (please help)

[URquattroGus]

I've now done 300 miles on my newly rebuilt AAN engine that sits in my quattro.

I seem to have a small leak/weep that shows on the corner of the head gasket area. To me it looks and feels like engine oil.



The catch tank and breather are located nearby, and at first i wondered if it could be oil vapour rising up, condesing on the bonnet and then dribbling down. Quite sure its not this really.

Have checked all hoses etc and cleaned down the area several times with brake cleaner and some rag.


I cleaned it down and after just 15-20 mins of engine idleing there was some oil there.


Could this be that the head requires re torqueing? It has arp studs and bolts.

Would it be a good idea to check torques? if so, what are they and what is the toghtening sequence??

Any ideas guys???

[URquattroGus]

Should have added that the head gasket is a fresh RS2 item.

[pasbogdan]

oil leaking from cam cover can be pushed to rear of the engine by air entering from the front(grille).It is hard to spot it because of the heat shield on the turbo side of the engine.
If you reqtified the head and the block at the rebuild the gasket should not leak

[JP]

ARP studs you need to get the torque setting that came with the bolt set mine were 65ft/lbs.

Torque up using the lube supplied, run engine up to full temp and leave to cool down over night. Re torque to peak torque setting only using correct sequence.

Then run it 150-200miles. Check it again by re torquing to peak torque.

Lastly check once more after 500 miles.

Due to the extraordinary length of the bolts they are very prone to excessive settling compared to other ARP bolts and have seen many a failed headgasket.

However putting that aside due to the location it is more likely to be the rocker gasket leaking so check this first as usually the h gasket goes first on the oil return of exhaust number one.

[Wheeljack]

Yes, re-torque after heat cycle. You will likely get a bit more turn on them. And use the values that came with the studs. I would check mine, but they are out in the cold, cold garage at the moment.

On a related note...there is a coolant passage at the edge of that corner that I have seen weep on many, many I5 engines. But that would be coolant, not oil.

Did you have the head/block resurfaced? That is another way to help ensure a good seal, especially with MLS gasket like the RS2.

HTH

[rs200]

you can try to re torque the bolts on head, but there is a little chance to be batter..

change the head gasket.. and if I remember well , you are not aloud to re torque the bolts on cilinder head when one time you pres it first time.. that is writen on WIKTOR REINZ head gasket... if it is metal gasket.. because that can caus gasket leek..

try, but there is no garanty

[rs200]

my experience of head gasket is that : If I today go to fit head gasket on engine, I do it like head gasket paper said.. than leave engine 24 hours , and than , do the same process one more time. and you will see that you will have filling that yesterday you done NOTHING, and how much space gasket still have.. it's important that you don't warm up head gasket..
try .. you will see..

[URquattroGus]

Guys, I'm not 100% sure yet but on very close inspection I did find two things, a loose union for the feed pipe that goes into the top of the catch tank and more importantly a the semi circular seal on the the top right hand side rear of the head that seals with the rocker cover appeared to be slightly scalloped in and weeping oil a little.

I had the rocker cover off and have re seated, and turned round the seal (it is quite scalloped, more so than the other one on the lhs top) Then torqued bac up to the correct 10 nm for the allen headed bolts.

Lets hope that sorts it! It's been a worry!

[DJones]

Guys, I'm not 100% sure yet but on very close inspection I did find two things, a loose union for the feed pipe that goes into the top of the catch tank and more importantly a the semi circular seal on the the top right hand side rear of the head that seals with the rocker cover appeared to be slightly scalloped in and weeping oil a little.

I had the rocker cover off and have re seated, and turned round the seal (it is quite scalloped, more so than the other one on the lhs top) Then torqued bac up to the correct 10 nm for the allen headed bolts.

Lets hope that sorts it! It's been a worry!

Angus, did you re-tighten the head bolts when the cam cover was off. As stated in the posts above you do need to heat cycle with ARP bolts from memory mine went about another 90 degrees to get to the torque.

Hope it helps.

Darren.

[URquattroGus]

Djones,

No, as I didn't build the engine I didnt have the balls to do it!

I think I should see if this sorts the problem and if not speak to him first. It's not the first time he has used ARP studs on the I5 so I am relatively confident. If it doesnt go away I'll be calling him in the new year.

Impoirtant as at the moment I'm only running in and on standard boost. I will be getting it mapped in the new year.

[URquattroGus]

Right. Good news is that I have worked out where the leak is coming from. There was maybe the tiniest amount from the semi circular seal at the back of the rocker cover, but it appears to be from the front lhs of the rocker cover.

It is leaking from the front LHS corner, but very slightly, it then gets drawn along to the back of the engine, just like several people said. Its drivable, but needs to be sorted!


Bad news is that the head thread on this corner is fooked!

It only partially tightened and I couldn't do it up to the correcty 10Nm on re instalation of the cover.

So, on the basis of this i thought i would try and clean thre thread up. I used my basic tap and die set. I matched it to a M6 1.0 tap and die. I wound the die around the allen headed with only slight resitance and only by hand. It didnt seem to change the thread, just clean it a little.

I then bravely put the tap into the head by hand to try and clean the thread. It seemed to be going well but the net result is that the thread is now well and truly ******ed.

The allen headed bolt won't do up at all.

So what are my options? has any one done a repair before?

Can I go for a slightly bigger tap and or bolt? or do I need to go down the helicoil route? Bit nervous about having to drill out the hole! any ideal what size I could go to, presumably m7??


In other news my 26 year old digital dasboard fried itself today, stopped working, then a puff of smoke, had to pull straight over and disconnect the battery then disconnect the dash, all in all not such a good day!

[willg54]

helicoil would be my vote depending on how much metal you have around. They're very strong! get the hoover running while you drill it!

[DJones]

Right. Good news is that I have worked out where the leak is coming from. There was maybe the tiniest amount from the semi circular seal at the back of the rocker cover, but it appears to be from the front lhs of the rocker cover.

It is leaking from the front LHS corner, but very slightly, it then gets drawn along to the back of the engine, just like several people said. Its drivable, but needs to be sorted!


Bad news is that the head thread on this corner is fooked!

It only partially tightened and I couldn't do it up to the correcty 10Nm on re instalation of the cover.

So, on the basis of this i thought i would try and clean thre thread up. I used my basic tap and die set. I matched it to a M6 1.0 tap and die. I wound the die around the allen headed with only slight resitance and only by hand. It didnt seem to change the thread, just clean it a little.

I then bravely put the tap into the head by hand to try and clean the thread. It seemed to be going well but the net result is that the thread is now well and truly ******ed.

The allen headed bolt won't do up at all.

So what are my options? has any one done a repair before?

Can I go for a slightly bigger tap and or bolt? or do I need to go down the helicoil route? Bit nervous about having to drill out the hole! any ideal what size I could go to, presumably m7??


In other news my 26 year old digital dasboard fried itself today, stopped working, then a puff of smoke, had to pull straight over and disconnect the battery then disconnect the dash, all in all not such a good day!

Angus,

Use a Helicoil it will be fine. Alternatively you could turn it from a bolt to a stud by using something like JB Weld to glue a stud into the head (which has the same thread as the original bolt) and use a washer and nut to tighten the cover down.

The green binnacles are b***dy horrible things make yourself up a nice analogue dash..

Darren.

[URquattroGus]

I got round the problem in the end without resorting to a helicoil, I just used a longer bolt and it worked a treat....

BUT

******! The leak as origionally pictured is back, and it's worse than ever.

Dash now repaired

I have just done 100 miles today and it was enough for the oil to go from approx the top of the dip stick to approx the bottom/add oil level. I say approx because the dipstick seems to be a pig to read, is this normal for these engines?

The back of the trans has a smattering, buty if definetly seems to be coming from the back of the head on that corner.

I didnt check the ARP head stud torques last time because I wimped out.

Silly question, I saw that the nuts were sort of star shaped, I then presumed I needed a special socket, but on second thoughts...,

will a normal socket fit and is it just so you can get more angles/a better fit with a non duo metric socket that grabs the corners but not the sides?

Starting to worry something is a amiss now! Please help.

[pasbogdan]

If the combustion chamber is not leaking to oil and/or water only the oil can not leak to the gasket.Not even old engines with paper gasket were leaking this way.Only in head and block were not machined(well or at all).
If you machined block and head it is not possible to leak.
Only if you have traped your cell phone between block and gasket when you mounted the head
One l of oil on the back of engine is a lot.Especialy in 100 miles.Your exhaust should smell bad,lot of smoke or something.
Isn't your engine leaking somewhere else?What about piston ring tipe and clearances?