Chattering noise from head after a track day

[JGood]

I think I'm going to run to the hardware store and get two 100psi gauges and put them on the HF leakdown tester, and re-test the engine. I will also pick up an oil pressure test kit.

What size is the m20's sender, and what is the pressure supposed to be? Does it change based on RPM/load?

[JGood]

The piece of shit HF tester uses proprietary gauge threads or something. So no go there.

But I zip tied the throttle open above 2k and went underneath with the stethoscope. Bingo. The noise is coming from the bottom end. Mainly the lower block and oil pan area. I might even venture to say it's specifically coming from the sump area. Ideas? Remember, it starts instantly at exactly 2k, not gradually.

[Jean]

Can't really add much to this thread, but good read.

[jlevie]

The piece of shit HF tester uses proprietary gauge threads or something. So no go there.

But I zip tied the throttle open above 2k and went underneath with the stethoscope. Bingo. The noise is coming from the bottom end. Mainly the lower block and oil pan area. I might even venture to say it's specifically coming from the sump area. Ideas? Remember, it starts instantly at exactly 2k, not gradually.

That is what I suspected. That noise is almost certainly rod bearings. There's a slim chance that it could be the oil pump, but the odds are against that. If it is the pump the noise should be loudest where the blank off for a distributor would be.

[Dave]

My rod bearing that spun started with a noise at a certain rpm and then got worse.

Good thing you have a spare. Put a crank scraper on it and overfill the oil a bit.

[JGood]

Damn it. My spare is the original motor, which has 270k miles. I swapped this 140k mile engine in last year as "preventive maintenance".

Guess I'll put that motor in and either do the bearings/rings/gaskets in this motor, or just get another used m20.

Questions: If it is a rod bearing, what exactly is making the noise? Did the bearing wear to the point where the rod is actually moving around inside of it? Will the rod likely be bad as well then?

[Dave]

rod end will be moving back and forth on the crank. The bearing material is worn away/gone and so there is now a gap between the rod and the crank.

I suppose you might get lucky and just put new bearings in, but I'd get the rod and crank checked out first.

[JGood]

Yeah, I'm going to just skip the whole rebuild idea then, I am not looking to spend north of $1k to put an m20 together. I've found a few m20's with ~100k miles for about $300, so I'll just go that route. I'll be sure to put a baffle or crank scraper in though. I'll need to do some research as I never really paid much attention to those discussions.

[Dave]

That is probably the higher percentage play. You can go over to the SpecE30 site and see what things people have done - scrapers and the Paul Poore oil pan seem to be the things that work. Even on old junkyard motors.

Whatever you do, if you go to the SpecE30 website looking for advice on oil issues, do NOT listen to anything by Ranger.

[nando]

That is probably the higher percentage play. You can go over to the SpecE30 site and see what things people have done - scrapers and the Paul Poore oil pan seem to be the things that work. Even on old junkyard motors.

Whatever you do, if you go to the SpecE30 website looking for advice on oil issues, do NOT listen to anything by Ranger.

lol, that poor guy. I think he'll probably have something to share eventually. I mean, he's been through 3-4 motors now?

anyone interested in a new glyco main bearing set? standard size, for later M20 blocks. Been sitting in my garage for 5 years now..

[Dave]

lol, that poor guy. I think he'll probably have something to share eventually. I mean, he's been through 3-4 motors now?

anyone interested in a new glyco main bearing set? standard size, for later M20 blocks. Been sitting in my garage for 5 years now..

I think he is closer to 6 or 8.

[Gruelius]

ive got the same symptoms, at exactly ~2k i get a ticking noise, regardless of wot or full vac engine running or not. cars been going fine for 5k kms tho, hasnt been getting worse, my mates 325i mtech 2 with low k's does it too. are you sure its not just valvetrain noise amplified due to oscilations or someshit? i had a really loud tick when my exh gasket was blown out, i think it may have happened again too.

[ldsbeaker]

I think mine's been doing that for about 3-5k miles. I parked it.
I'm not really into trying to control a car that suddenly has a holey block.
New engine going in.

I'll be sure to check for play at the bearings and try to document/video results.

[JGood]

ive got the same symptoms, at exactly ~2k i get a ticking noise, regardless of wot or full vac engine running or not. cars been going fine for 5k kms tho, hasnt been getting worse, my mates 325i mtech 2 with low k's does it too. are you sure its not just valvetrain noise amplified due to oscilations or someshit? i had a really loud tick when my exh gasket was blown out, i think it may have happened again too.

Not sure, I swapped in a 99k mile m20 with a crank scraper and called it a day.

I got a stethoscope and narrowed the noise down to the bottom end. Has to be a bearing or the oil pump. Blowing the motor at a track day = $200 track day + $300+ tow home + $300 engine = $800+. Not worth the hassle IMO.

[jlevie]

lol, that poor guy. I think he'll probably have something to share eventually. I mean, he's been through 3-4 motors now?

It is more than that, but to be fair at least two and probably three of Ranger's motor swaps weren't because of anything he did. And another was from a severe overheat in a winter enduro race when the engine lost all coolant. Because of the cold air flowing over the tstat housing, the temp gauges never budged. The best preventative for that sort of failure is to monitor cooling system pressure with a 3-4psi pressure switch and turn on a warning light on loss of pressure.

The latest in Ranger's engine is a week spent at Metric Mechanic building another engine. The MM folks allowed him and another Spec E30 racer to participate (and learn) during the engine builds. That was pretty righteous of MM.

Junk yard engines, even sub 150k mile ones, are a roll of the dice unless you can hear the engine run, check the oil pressure. and get good compression and leak down results. I have three sitting in my garage right now. All of the engines had less than 100k on them. One engine has low oil pressure, another has poor leak down numbers, and one was good enough to use in a Spec E30. Granted I didn't pay much for those engines, but there was a good bit of labor involved in getting them and installing them in the car only to find out they weren't usable. For a track or race car it would have to be an emergency for me to run a used engine now. A properly rebuilt engine is the way to go.