Oil in cylinder head UPDATE

Post Sun Jan 22, 2006 10:39 am

Was going to adjust valves this morning, took rocker cover off and started up and to my horror there is a torent of oil coming up from under one of the head bolt heads. I guess this would account for the amount of oil I've been getting through my filter lately. Is this a head gasket failure?

Post Sun Jan 22, 2006 7:08 pm

Check and see if the head bolt isn't torqued down properly ?

Post Sun Jan 22, 2006 9:38 pm

Oil feed to the rockers and cam comes up through one of the head bolt holes, but is supposed to go into the cam bearings, not come out under the bolt head. Must be loose.

Post Mon Jan 23, 2006 12:18 am

the head bolt in question is the centre on the exhaust side, with the hole just above, I did try to torque it some more but was worried it might crack off. Will give it another go tomorrow. Thanks for the help.

Post Mon Jan 23, 2006 8:50 am

That's the right bolt hole.
Does it have the thick flat washer in place under its head.
If you think it (or any of the other bolts are loose), back them off one at a time and torque them up to the correct figure.

Post Mon Jan 23, 2006 4:16 pm

Thick washer is in place, just had a tighten before I got this post it's at 75 foot pounds and still gushing out, hasn't reduced the flow at all. Will slacken off and re-torque. All the bolts where done as per the Bentley manual, only problem was in my excitement to refit I didn't clear the old oil/sludge from the bolt holes. I remember ther were a few full of oil, but not which ones.

Post Mon Jan 23, 2006 4:49 pm

I'm sure somebody has put a curse on this car.
Head bolt has sheared off! Why is there never any beer in the house when you need it?
The bolts were torqued to 75 foot pounds, this was doing the 22ft then 90 then 90. I would have thought that worked at more than it should have. Anyway was just trying for that extra half a turn, nice and slowly and whack. It look's like the bolt may have sheared off in the thread, can this be drilled out, are they stainless?
Decided to start the car with the broken bolt in place, don't know why, but was surprised when the bolt shot over the wing, and so much oil there was a 3 foot arc of oil all over the wing and strut. I'm going to the offy.
Seeing as I am stupid I may as well drink myself the same!

Post Mon Jan 23, 2006 6:48 pm

LOL! Sorry for laughing but the image of that happening was so funny. Hopefully you'll get away with just a fecked bolt.
Worst case the head is cracked somewhere which may be why the oil is coming up as much as it is.

Post Mon Jan 23, 2006 6:57 pm

If I didn't laugh I would cry, what's the best way of getting the bolt out, drilling? It looks like about 20mm of bolt is left in the block. If it was drilled I guess the system would need a flush?
I bet it's not that easy and I bet the heads buggered, and then it will be something else.
As my old mum used to say "every silver lining has a cloud"

Post Mon Jan 23, 2006 7:20 pm

Do I take it you,ve taken the head off again?
This bolt won't be rusted in place like a normal sheared stud. If you try to drill it with a normal drill bit it will probably dissapear further down the block.
Depending on how flat the broken end is, you may be able to wind it out with a screwdriver. Failing that, get hold of a reversed drill bit (one that turns anticlockwise). This will wind it straight out once it bites.
Interesting why this bolt sheared.
You put the head on yourself didn't you?
Hope you used new bolts with torx heads.
Now the bolt's out of the way, can you see why it was leaking? It's just a steel washer against the alloy head, but it normally doesn't leak.

Post Mon Jan 23, 2006 8:08 pm

Brian, haven't taken the head back off yet. Fitted it myself, used new torx head bolts from ECP's. Just had a quick look, the main hole sits in a recessed circle about 1mm from the surface the washer sits on and there is a drilled hole around 4mm and a tiny bit of it's footprint overlaps the recess, I would bet the car that the oil is sneaking up through this hole, there seem to ba a few of these holes in the same positions, but not on every bolt hole. The head was a new bare one from ECP, according to the previous owner. It does look very new. What I don't understand is why it didn't leak before?

Post Tue Jan 24, 2006 7:16 pm

Used new bolts, but old washers.

Post Wed Jan 25, 2006 5:51 pm

Took the head off today and the gasket was mullered where the oil has been coming up I guess.

The underside of the head has another partially drilled holed intersecting the bolt hole where the trouble is.
Fitted a new gasket and the oil is still coming out under the washer.
I couldn't see any visible probelms with the head, like craks or the like.
Think I might break it!!

Post Wed Jan 25, 2006 9:26 pm

DazzyA wrote:Took the head off today and the gasket was mullered where the oil has been coming up I guess.

The underside of the head has another partially drilled holed intersecting the bolt hole where the trouble is.
Fitted a new gasket and the oil is still coming out under the washer.
I couldn't see any visible probelms with the head, like craks or the like.
Think I might break it!!

Oil is supposed to come up the bolt hole, it's just not supposed to come out under the washer!

Post Wed Jan 25, 2006 11:37 pm

How much should come up Brian, I can't see a metal washer stopping the amount that is coming up under such pressure. What would happen if I took the washer off.
The old bolt came out just as you said by the way.
Maybe I'll take to the garage and get them to have a look.

Post Thu Jan 26, 2006 12:14 am

No idea what the oil pressure is in the bolt hole, but it's not at full pressure as you would measure on an engine oil pressure gauge.
It's the oil feed to the cam bearings and spray bar, and I've never seen any leaking from under the washer when I've run an engine with the rocker cover off.
Steel washer on alloy should be a reasonable seal, if the head area under the washer is flat and unmarked.

Post Thu Jan 26, 2006 12:24 am

Therein lies the problem I think. All the bolt holes have a slightly bigger circle around them which is about a 1mm recess. Oart of that recess is intersected by a small hole above(all the inlet side bolts have these little holes, but only this one on the exhaust side).
When the oil rises up the bolt hole it must fill this void under the washer, but as this small hole is mostly outside the washer the oil is coming out there. Maybe I coud try a bigger washer. Are these "recessed" area's normal or has someone used bolts without washers that have "cut in" they seem about the same size.

Post Thu Jan 26, 2006 12:28 am

I've never noticed any recesses where the washers sit.

Post Thu Jan 26, 2006 12:33 am

I took some pic's last night will put one up.

Post Thu Jan 26, 2006 12:40 am

Not sure how well you can make it out.

Post Thu Jan 26, 2006 11:31 am

Put the bolt in without a washer and it sit's exactly in this recessed area, as every bolt hole has these I assume at some point no washer's have been used and considering I have a receipt for the new head, bolt set, gasket set, leads, dizzy, cam belt etc... doesn't quite add up, again.
Anyway, how much oil is fed into the head, the spray bar works fine and there seems to be oil fed from both ends.
Always remember to reconnect all hoses before taking for a spin!!