Daltuhn

2001 S2000. 116,000 miles. Rough idle started around 95,000. No idle at 109,000. Cleaned IAC, replaced MAP. Idle returned but was rough. Abnormal oil consumption last 6,000 mi, but no blue smoke or burnt oil smell. No idle at 115,000 mi again. Replaced IAC, cleaned MAP port, valve adjustment. Idle returned but was rough. Compression test #1 210 #2 135 #3 75 #4 172. Leak down test: #1 10% #2 did not do #3 80% #4 40%. When conducting #3 leak down test, I could hear air passing between 2-3. Diagnosis: Blown head gasket.

Additional info: Car never overheated or ran hot. I haven't pushed it or drove abusively in the last 2 years since it is my daily driver. Occasionally bring it above 6500 rpm, but rare. Lots of highway miles.

A. Am I way off mark?

B. If the head is warped, can I get it machined 10,000ths, or are the clearances to tight?

C. If I machine the head, should I replace timing chain and tensioner?

D. Should I replace the bolts/studs when doing the head gasket? Could it be stretched bolts as the cause of the blow by on the cylinders?

E. Anything else I should watch out for?

I'm planning to start the tear down in 6 days. I researching, ordering, and prepping now. Any help and insight would be greatly appreciated!

rxrotorless7

I would say your diagnosis is correct, but not sure why the head gasket would let go even at around 100k miles. Are you the original owner? Any engine work done on it before?
I just rebuilt my f20c a couple months ago and the factory service manual will be your best friend when doing the rebuild...

Daltuhn

Thanks. I bought the car when it was 4 years old, but it only had 4500 miles on it then. I've put all the rest on it. I downloaded a great service manual. Should be a fun job.....

Muggus

I just did my HG not too long ago. Pretty easy on this car actually. I would definitely get the head checked and machined. When i did mine i left the intake manifold on to save some time and not have to buy a new gasket. It was kind of annoying because it makes things harder to get to but once you figure it out its much easier. For instance if you leave the manifold on just unbolt the head and lift it up a bit and you can unbolt the thermostat housing form the head fairly easy and just leave the hoses attached. I tried taking the hoses off at first at it sucked.

Daltuhn

Good advice. Thanks!

4forall

Seems like sounds deduction to me. Good luck and like everyone said service manual.

P.S.- Why drive your car another 6,000 miles when as you described had no idle at all?

Daltuhn

Thanks for the vote of confidence. I found a machine shop that will turn around my head in less than 8 hours. Looks like it's tear down on Wednesday and rebuild Thursday night and Friday morning. I have a good manual I downloaded. My gasket kit arrived today. I gotta pick up some liquid gasket and coolant on my way home tonight. Other than that, bring it on.....

The idle returned at 109 after some work, but it was rough. I lost it again at 115. After the valve adjustment and IAC replacment, it returned again, but was rough. Compression and leak down tests at that point showed the real issue.

Should I video the process for the masses? If anything, it might make good comedy.