13 replies to this topic

[Danny Boy]

Well my car wasnt starting about a week ago and it turned out to be water on the plugs so i thought it would be the head gasket, however i have done a compression test and all four cylnders are around 150 psi with no more than plus or minus 5 difference. i replaced my plugs and its been running ok apart from loosing some water. i also noticed there was some oil collecting on the edge of the head gasket where it sticks out a little so i did anther test got the same results but noticed that when testing cylnder no. 3 water dripped/seaped from the gasket (only like 1 drip a second) what could this be??? ive got a video of it leaking but my fone wont connect to my pc so ill post it later!!

[Dan]

Compression tests reveal very little. Did you do the test hot or cold? The only test that will tell you for sure if something is wrong is a hot leakdown test, this needs special equipment.

[Danny Boy]

i did it hot (think thats right??) i take it that that special equimpemt costs a lot of money? im pretty sure its the head gasket that has gone as oil and water (mixed together) is seaping out from between the cylnder head and block!!! ive changed the hg about a month ago what did i do wrong? is it actually possible for water to seap out like ive described without effecting the compression in the cylnders?

[Big_Adam]

You sure the head isn't warped. Or might just be a C**p gasket. You get a copper one?

[Danny Boy]

Yeah used a copper one! pretty sure the head isnt warped i took it to quasar engineering where they checked using a straight rule and feeler gauge (is this the correct method?) they said it was fine!

[Big_Adam]

I would have "borrowed" a DTI and a mill but sounds good to me.

Well I'm out of idea. All torqued down right isn't it. Been told to do it twice in the past.

[Danny Boy]

yeah it all tightend up i also got told to do it after the first 100miles so i did and they didnt need tighening they where all fine!!! i think i will just do it again doesnt take long im just puzzled why im leaking water out of the gasket and still getting a compression of 150psi across all 4 cylders???

[Dan]

Yes, you can still have good compression with a leaking head gasket. That's why a compression test isn't always useful.

When you torque it down, you must let the engine heat up to temperature and cool down once. Then release and re-torque each nut, in the same sequence as fitted. That is immediately, after just 1 heating cycle and not after 100 miles. The head isn't torqued until that's been done and will pretty much fail every time if you skip this part. And don't just tighten the nuts, release and then re-tighten each one. Don't be tempted to release them all and then re-tighten them all either as that will almost guarantee a leak. And don't rev or drive it while it's heating, just start it and let it idle up to temperature gently before switching it off and letting it cool fully.

[Danny Boy]

Ok will do that looks like im gonna have to do it tomoro because i was driving in it tonite and the bypass hose split ive replaced it before with a new one so the only reason i can think of it going is because exaust gasses blowing into the coolent system again is this possible??? i well missed drivin the mini tonite everyone seamed to be out and about in there mini's and the car i was using (pug 207 1.4) is pants compared to my mini although more reliable!!!

[Danny Boy]

Ok ive fully heated up the engine for about 40mins then let it fully cool down for about 5 hours then fully realese nut number one and retourqued it up then number two so on and so on does that sound right was itok to let it cool down for so long i just wanted to make sure it was fully cooled down!!!!

[Dan]

It's the right thing to do but it will only work with a new head gasket. Once it's started to leak there is no real way to re-seal it. You might be lucky but if you find it is still leaking you will have to change it.

[Danny Boy]

It's the right thing to do but it will only work with a new head gasket. Once it's started to leak there is no real way to re-seal it. You might be lucky but if you find it is still leaking you will have to change it.

sorry dan forgot to mention ive actually changed the head gasket lol so hopefully all shall be well now!!!

p.s is there anything else i need to do i.e drive it less aggressivly for 200miles or something??

Edited by Danny Boy, 15 June 2007 - 03:31 PM.

[Dan]

So long as all the push rods went back in the holes they came out of, no running in is required. If they got mixed up then you should let it run in for a couple of hundred miles. Re-set the tappet clearances now that you've re-torqued the gasket, and do them again in a month.

[Danny Boy]

So long as all the push rods went back in the holes they came out of, no running in is required. If they got mixed up then you should let it run in for a couple of hundred miles. Re-set the tappet clearances now that you've re-torqued the gasket, and do them again in a month.

yeah ive put push rods back in the same holes and done the tappet clearences thanks alot for helping!!!!