Going to Replace Head Bolts

[603Racing]

I'm going to replace the head bolts in an effort to stop the head gasket from leaking oil. I don't have any questions, I'm just going to post my method and the results.

The motor is a m20 from an '89 e30. Currently the head leaks slightly less than 1/2 quart of oil every 500 miles or so depending on how hard I drive. The leak is between cylinders 3 and 4 on the exhaust side. Head gasket was replace by PO when the head was rebuilt, about 2 years and 10,000 mile ago.

I will be replacing the bolts one at a time in the Bently pattern using TTY (stretch) bolts.

[Cabriolet]

waste of money. if the oil has leaked the gasket is bad. change the head gasket.

[sayed ali]

waste of money. if the oil has leaked the gasket is bad. change the head gasket.

+1

And make sure to get a good quality gasket + clean installation, no problem of putting a new studs but the gasket is the issue IMO

[603Racing]

Both of you could very well be right. But for the 45 minutes of time and only $20, I'm going to give it a shot and share the results. Definitive answer to come.

Appreciate the feedback.

[LagunaVert]

You can't really replace them one at a time and do it according to spec bc spec requires they be tightened in a pattern. Buy a headgasket and timing belt kit and do it the right way. It can be done in a day and you will end up needing to do it later anyway.

[tinkerputzer]

Actually you can. Thats how bmw did it when they converted the hex style head bolts to torx style hed bolts.

[jlevie]

Actually you can. Thats how bmw did it when they converted the hex style head bolts to torx style hed bolts.

Correct. You replace the bolts in the same order as the tightening spec.

[603Racing]

I replaced the head bolts Sunday. I did them according to how BMW replaced them, just as tinkerputzer stated. I didn't have any issues replacing them and it only took about 30 minutes. So for $25 and 30 minutes of my time it is well worth the effort even if it only buys me another year on this head gasket.

Plus, it appears as though the shop that rebuilt the head reused the old bolts as the head had hex bolts on it. So now at least I know my head bolts aren't going to break and destroy my head.

I will post updates on the oil leak and gasket condition as I accumulate miles. First update is that the car runs fine. Had a friend of mine do a compression test when I was at work yesterday, tested out at 160, 160, 160, 160, 159, 160. After 50 miles of driving, no oil so far. I'll run it a little harder today and see what happens.

[603Racing]

Second update:

Car still running great in 95*F weather. Have about 400 miles on the car after replacing head bolts. About 300 highway miles and about 100 city (stop and go traffic) miles. It appears as though there is a bit of oil on the outside of the gasket/head, but it's not running down the block like before. Oil has remained at the same level on the dipstick. I'm not sure if this is residual or if it still has a very minor leak. I will keep an eye on it and post one more update at the 1,000 mile mark.

[brianao34]

Good job

[603Racing]

Final Update:

So the oil leak is back to what it was before the head bolt replacement. I've put 1,000 miles on the car and it has leaked about 1/2 quart out of the same spot in the head gasket. So, I'll be doing a head gasket replacement this winter.

I'm still glad I did it though, because I had the old style bolts that are know to break.

[jlevie]

When you do the head later, take it to a shop and have it surfaced. Then use a BMW OE head gasket and new head bolts.

[Cabriolet]

damnit. i love being right but i feel sorry for you. just do it right next time, its only like a $200-300 job.

[603Racing]

Yeah jlevie, I plan on doing that this winter. Darn the luck, just put this motor in the car too, would have been a cake walk to do this on the engine stand when I already had the timing belt off and was replacing all the seals. I was trying to get away with cheap and easy fix... no such luck.

I appreciate not getting steamrolled by the thread bashers. ...and now we have a real life example where just replacing the head bolts does not fix a head gasket leak.

[603Racing]

Final part to this story...

The head gasket finally started letting oil and coolant mix. I pulled the head, gasket was apparently leaking because the head was warped. It was off about 3 thousandths at cylinders 3 and 4. Had it machined and put on a new gasket. I finished up the job yesterday and after flushing the coolant system several times it's up an running. Going to adjust the valves Thursday then take it for a nice long drive... checking the oil and coolant about every 5 feet, lol.