Hey all, (1999 D1)
So all was normal this morning. drove her about 100 miles today and in the course of that, somewhere I have developed a knock.
It's always made a bit of noise under load and I just came to expect that being that the exhaust manifold gaskets were re-used after the trans job. However, I had been noticing it at lower and lower RPMs with less load. Now it's starting at idle and goes with engine speed so I'm almost positive it's internal. It sounds like it's coming from the bottom and it started as a very light knocking but now, after I drove the 30 miles home it has gotten much louder. Girlfriend even asked me if that was normal. I honestly don't rightly know what to do here. I just changed the oil with 15/40 Rotella, and a bosch filter. I honestly can't believe this has been quite so one thing after another. Any help is appreciated...if anyone could walk me through what to check that would be great. As before it's nearly impossible for me to avoid driving her...I seriously need help at this point...I don't know what to freaking do.

 

is there a chance it is a slipped liner? hook up a real oil pressure gauge to see where you are at

 

don't know if it is a slipped liner. If that's the case would it come and go kind of intermittently? It gets louder and quieter randomly as I idle. I don't know which is worse at this point.

 

So if it is present at idle, at one volume or another, why not hunt for it?

Take a yard stick. Flat side aginst your ear, touch other end to various spots on valve covers, things that rotate by the belt, etc. If it sounds like coming from inside the engine, but lower than the valve covers, try unplug spark wires one by one. The idea is that without a fuel/air explosion in that cylinder, connecting rods and such will not knock as loud.

Oil PSI test would be a good idea as well.

 

Going to install an oil pressure gauge today and see what happens. About to have to go and drive her to an appointment. We shall see what happens this morning.
Its very, very faint today. I'm actually fairly sure that I bought it sounding like this now that I know what to listen for. I am going to drive it about 200 miles tomorrow, but theres a good shot I can get my friend who specialises in this kind of stuff to have a look at it. I am however going to try and throw in an oil pressure gauge later today.

 

I have had aluminum water pumps on aluminum engines sound like the engine is bad they can get crazy loud when the bearings go and it echos through the all aluminum engine, not trying to get your hopes up just sayin it may not be the crank/rods

 

Thanks Tom for the response-feel like you could be right. Is there anything noticeable from the outside when the water pumps are on the way out? There was a good amount of sediment in the coolant as well...
Ok so a little more information after messing with it a bit after my appointment.
Ran some lucas oil stabilizer through it and it's still knocking. I put it into the gap in the oil drain straight into the rockers with and oiler and some marvel mystery oil. Also put some marvel into the gas for kicks and giggles. No appreciable difference although I now know when (and a rough idea where) the motor is knocking. Seems to knock after throttle is applied and when it drops back to idle. No noise before rev and during rev, only when you let off. Lasts for about 5-10 seconds and goes back to normal. It seems to come from the mid-section of the motor-I believe from either the cam or the crank. Cant isolate between the two, although it seems that the crank pulley wobbles a bit as the knock is happening. It's not VERY loud, but definitely noticeable. Any thoughts? Starting to think rod bearings-but possible cams/rocker arms too. Where should I start?

 

crank pulley should not wobble even if there was a bad crank bearing, you sure the pulley bolts are tight? in my experience when bearings go and start knocking it knocks all the time just gets louder with rpm and engine load, does the engine run smooth?

definitely try some of what buzz said

 

Perhaps the wobble is the water pump moving the belt, they love to wobble when getting ready to jump off the cliff. You can listen along length of valve cover hunting for noise underneath.

 

More updates on the knock. It keeps getting more and more random. So at start from neutral cold, it is totally silent as can be. When you put it in gear the clicking starts. engine is still running smooth as glass but this knock seems to be happening louder and louder. My thought is this-if the shop who did my trans removed the flywheel (which I am fairly sure they did to replace the TC) could it be working its way loose? That would explain the no noise at cruising speed I believe...I have heard engine knocks before (believe me, worked at a shady used car dealership where stuffing banana peels in the valve covers was an acceptable solution for chrysler 2.7s) but they all seem to go throughout the rev range. This just stops above like, 1200 RPM. And gets worse the more abruptly power is applied. Wishful thinking, but give me your thoughts...
And by the way, the oil pressure seems to be good. I just changed the oil again-no difference and clean as can be...

EDIT: also sitting with it stopped in D makes it absolutely horribly loud...and goes away again after you pull away.