Engine knock @ 1700-2300

[rstutler]

Hi everyone. I'm new to the Supra Forums so let me introduce myself first. My name is Rob, I was in the Army, deployed, and when I got back, I noticed a beautiful Maroon 87 Supra 7m-gte. Talked the guy down to $2000 for the car. Drove it back home and didn't notice the knock until I pulled up to a friends house in it. He gave me that look like "oh sh!t." But anyways, my car has been sitting at my pop's house for about 2 years now, I decided to change the fluids and start her up again. No problems. Still she has a knock, so we started taking things apart. We can't figure it out, because from my experience, rod knocks usually increase when given some throttle, but my baby only does it around 1700-2300, doesn't do it at idle, and doesn't do it after 2300... When I changed the oil, I didn't notice any shavings... (which brings up another point... Why the hell did Toyota make that damn Oil Filter so damn hard to get to?!?!) Someone suggested it might be the turbo after it spools, so we took it apart, no shaft play, spins freely... I have yet to pull the spark plugs and see if it softens the knock. Anyways, just trying to see what you guys think it could be, because I'm lost. When I first got it, I ran the crap out of it and nothing happened... Oh and my boost gauge isn't reading any boost, it used to before it sat there for a while..(Mind you I know very little about turbos.) What do you guys think could be causing the knock? Oh, it doesnt sound like anything pounding really, more like an highly audible tongue clicking sorta sound? (bad choice of words...)

[rstutler]

Oh and possibly suggest some different ways to find out exactly what is causing it. Thanks!

[ddmcse]

check the condition of the main belt pulley on the crank , try and move it by hand

[h8z2luze]

That sounds like what happened to my 89 n/a turned out it was a rod bearing... started out soft then got louder and louder. I wouldn't drive it to much lol.

[Chambers]

Originally Posted by rstutler

...Oh, it doesnt sound like anything pounding really, more like an highly audible tongue clicking sorta sound? (bad choice of words...)

I know exactly what you mean by that sound. My car has a "knock" that you can really only hear in that rpm range. I had my father take a home made stethoscope (a piece of small diameter pvc pipe, lol) and listen around the engine while I held it around 2000rpms. He tracked down the sound coming from the exhaust side cam, cylinder 3 or 4. I took a listen and it was defiantly louder on the exhaust side right in the middle of the engine, length wise.

The valve train in the Supra basically has shims that the cam lobes push down opening the valves, if they wear incorrectly that could very possibly create the "knocking" sound. I haven't had a chance to take the valve cover off my car yet to see if it is a shim, but its something I plan to do soon.

Hope this helps a little, it's at least a place to look.

[rstutler]

Originally Posted by Chambers

I know exactly what you mean by that sound. My car has a "knock" that you can really only hear in that rpm range. I had my father take a home made stethoscope (a piece of small diameter pvc pipe, lol) and listen around the engine while I held it around 2000rpms. He tracked down the sound coming from the exhaust side cam, cylinder 3 or 4. I took a listen and it was defiantly louder on the exhaust side right in the middle of the engine, length wise.

The valve train in the Supra basically has shims that the cam lobes push down opening the valves, if they wear incorrectly that could very possibly create the "knocking" sound. I haven't had a chance to take the valve cover off my car yet to see if it is a shim, but its something I plan to do soon.

Hope this helps a little, it's at least a place to look.

Wow man, definitely let me know what you find out. Have you been running your Supra at all?

[Chambers]

Yea, I drive it every day. I always let the engine run for about 3 to 15 mins to make sure the oil gets to all parts of the engine, I think the "knock" came from using the wrong oil. The previous owner ran strait 40 weight in it and I know he was hard on it because he drifted it, so I can only imagine that the "knock" developed from those factors.

I stopped by a Toyota dealership today to see if they could get me the valve shim remover tools and no luck, they didn't have any for them selves to use and they couldn't get them. If it is the shim making the "knock" then I'm going to have to fabricate something to get it done.

Yea, I'll let you know what happens. I think I will take the valve cover off this weekend when I do the sparkplugs and wires. Good luck!

[h8z2luze]

Again thats how mine started out exactly what you guys are saying. Louder on one side I had a stethiscope as well but one made for just that and i know the sound your hearing trust me lol Like I said mine ended up being a rod bearing.

[abhattan]

It could also be a wrist pin knock. You don't hear those when the engine is at a steady speed. You will hear it that spit second after you hit the gas or right when you let up off of the gas. If you keep the engine oiled, you should be fine, if that's what it is!