MM951

Why did I have to talk about replacing the 951 in its presence both last night and today This literally appeared 10 minutes after driving the car. It has been running great, just took it for a drive, gassed it up, added 1/2 qt of oil and came home. 10 minutes later I was about to leave to go to school and I hear what is most certainly rod knock. I have a suspicion as to what caused/contributed ...

At this point I'm not sure what to do (part it, replace the short block, or get a 968/ E36 M3)

carlege

Does everyone assume when the car is knocking that the crank shaft is useless? Why cant you just replace the Rod Bearings?

MM951

I'm pretty sure I could get away with replacing the bearings, but there is another ~$900 worth of stuff that has been bugging me that should be replaced at the same time - all of which would be money I would not see back - and I don't have the money/time to do that right now. The car is also really rough on the exterior (was vandalized..scratches/dents on every panel) and I don't want to invest any more in it.

What I am leaning to right now is giving my mother all the nice parts (968 wing, interior - particularly my seats-, 951 front end, etc) and parting the rest if I get a M3 or - more likely- save the the turbo parts and get a 968......

theedge

carlege

from the pictures it looks like a well cared for car. Ball is in your court.

MM951

I do take good care of it, it has been great for these past 15-16K miles and there are TONS of good parts on it - all virtually new. I did not care about spending money on this. Everything is new/good shape minus a few exhaust leaks, a power steering leak, and ball joints (I bought rebuilt control arms that .......sucked)

Edit: I know Brian...giving the parts to her sounds stupid, but she expressed an interest in helping me with an interest free loan to get a cheaper replacement car in exchange some of my parts for her 86 N/A... I'm not sure if I will take her up on it as I hate borrowing money, but I have been wanting a replacement car for some time and can't afford any downtime right now (lots of school, work, flying 7 days a week)

carlege

I understand not wanting to put X amount of money into the car that you cant get out but whats the difference between that and Buying another car thats going to depreciate as much or more? You dont want to spend $900 but you will buy a car for 7-10k ?

Looking at if from my point of view... you know whats wrong with the car.. you could buy another car and surprise it could throw a rod and such and such. Seems like you have a workable car with tons of potential since it has so many new parts.... and you know how to work on it.

Chris White

If the sound just appeared on start up then its not rod knock. More likely a really bad lifter.

Rod knock shows up first on a hot engine right after tha hard use, it almost never shows up for the first time after start up - oil is cooler and thicker and will mask the knock untill warmed up (unless its massive knock - and then you should have heard it last time the engine was running).

INURGRL951

If you started it and heard a knock it just my be a bad motor mount at 2100rpm's can sound like a bad knock just setting and holding the rev's there...just an fyi.It's a far reach but I have seen it.

MM951

Hey Chris, thanks for the input. I did drive the car "hard" shortly before hand. I took a cruise out, got some gas, checked the oil saw it was 1/2 on the dipstick, added a 1/2 qt., and drove home - boosting it a few times (max 90mph in 3rd) when I noticed some oil smoke come into the cabin on hard acceleration. I thought maybe I just developed some oil leak or some of the oil I added missed, so I just brought it straight home and did a hot compression test. 130 +/- 5psi on each cylinder. 10 min later I start it up and there is Mr. Rod Knock

FWIW, I watch my oil pressure like a hawk and take note of every sound. I have had some exhaust leaks and heard a slight tapping - I suspected it might be a bearing, but it sounded more like an exhaust leak. I asked everyone I knew if they heard it and nobody else could. In fact, right before I left on the last drive I asked my friend if he could hear anything... So the signs could have been there, but either way it progressed rapidly.

porshhhh951

Damn that sucks.

sebastian944

you said you had a suspicion to what caused it, what did you do?

MM951

So when I get remove the ignition wire from one cylinder at a time, the knocking never goes away ?? From what I understand, you can usually kill the knock by cutting ignition at a cylinder to determine which one it was. Any thoughts?

I'm eyeballing parts and it looks like if I can somehow get away with just replacing the bearings and all other stuff that comes off...will be about $300. I'm just a bit sketched out by the idea as that as this is a good amount of work and if it doesn't fix it .......

I still have to replace the motor mounts, steering rack, control arms, get my cross-over/headers repaired, and fix the PS leaks while this is apart, because it would be stupid not to fix them while they are off. So that would be at best another ~$1K in parts. I really like the car, but I'm hesistant to drop that kinda money on it when it does not look so great. If I got a 968 I could make all of my nice performance parts and that 2.7 head I have sitting around useful....

Just for reference, I always let the oil (20w-50 rotella and canton racing cartridge filters) warm up before giving it any higher RPMs. Usually shifted by 6K and never even brought 4th past 120-130ish.



When I was having issues with the 1st gen Maxtronic box I was dumping obscene amounts of fuel into the oil - even though I changed the oil no less than 5 times in 50 miles when I had that issue - I think the contaimanted oil might have contributed.

Chris White

How's the cold old pressure? If it's near normal then it's not rod knock ( I don't think it is)

MM951

I'll start it up now and get right back with it