Grinding noise at 2500 RPM...

[6o4turbo]

Just changed my oil today, switched over from dino to synthetic. Running 20w50 royal purple, very happy with it thus far. Raised my oil pressure about 40%

After a bit of driving, I noticed a noise, a sort of grind, rattle coming in at the 2450 RPM range making noise till' about 2600 RPM. No noise at any other rpm's, higher or lower. Appears to make noise in all gears.

From inside the car, it sounds like it's coming from the tranny area.

Any ideas as to what could be causing this?

Perhaps worn out synchros? There is no noise when shifting, it's only while in gear, which makes me want to rule this out.

Doesn't sound like knock, and if it was knock it would progressivley get louder with the RPM's, correct?

It couldn't be related to switching from the dino oil to synthetic, could it?

I'm thinking it may be vavle related?

Fresh motor, 3000 Kilometers.

Any help would be appreciated, thanks.

 

[6o4turbo]

Anyone?

 

[Yellow 13]

I doubt its rodknock. Try simply changing the oil in the trans and see if that helps.

Ive had my trans make grinding noises that go away after some fresh oil.

75w90 IIRC.

 

[6o4turbo]

I doubt its rodknock. Try simply changing the oil in the trans and see if that helps.

Ive had my trans make grinding noises that go away after some fresh oil.

75w90 IIRC.

If it was tranny related, would it only make noise in a select rpm range though?

 

[Yellow 13]

Well, you said it was coming from the trans area.

Is it there when you free rev it? If theres nothing then its probally not RK.

How loud of a grinding is it?

How long ago did you change the oil? Did you fill it up to the correct amount?

Sorry for all the questions but diagnosing something over the internet is a bit different from being there in person.

To get to your question...Yes. Since your saying its through all the gears im guessing its something they all have in common though.

 

[6o4turbo]

Well, you said it was coming from the trans area.

I'm not %100 sure of that, I can't here it when I rev it from underneath the engine bay so much. It's only in the car you can hear it, sounds like its coming from below the shifter.

Is it there when you free rev it?

I just went out and did that half an hour ago, as far as I can tell it ISN'T there when I free rev. But it's hard to say.

How loud of a grinding is it?

It's not nearly as loud as full out rodknock, it's quiet enough to make it difficult to pinpoint. If it is rod knock, it's the very beggining of it.

How long ago did you change the oil?

About 5 hours and 50 Kilometers ago.

Did you fill it up to the correct amount?

Put 5 qts in then topped it off with another 1/2 qt when I got home. Didn't rev it or run it hard.

The new motor has never run low on oil, though it has had low oil pressure issues when it heats up.

 

[Yellow 13]

Howd you get 5 1/2 qts of oil into the tranny?

I was talking about the transmission oil, how long ago has that been changed. and did you use dino or synth?

If you want to check if its rodknock pull a plug wire 1 at a time and see if it goes away, if it does that cylinder has RK.

 

[6o4turbo]

Howd you get 5 1/2 qts of oil into the tranny?

I was talking about the transmission oil, how long ago has that been changed. and did you use dino or synth?

If you want to check if its rodknock pull a plug wire 1 at a time and see if it goes away, if it does that cylinder has RK.

Trans oil was changed 3000 K ago when I swapped the new motor in.

It's Dino oil in it.

I'm going to find out tomorrow if the noise can be heard a free rev for sure, if it can I'll pull the plug wires.

Thanks yellow.

 

[Yellow 13]

NP.

 

[MDCmotorsports]

It might be a freak thing as in the pilot or throw out bearing took a giant sh!t.

I know my input shaft makes some mad sounds when the car is in neutral and sitting still.

 

[6o4turbo]

Alright, well I just checked, it definitley does make the sound when free revving.

It's still in that same RPM range.

It sounds more like a jingle than a knock though, like something is rattling around in my tranny. But I don't see how it could be tranny related if it's only in that certain RPM range...

Given this, any possible other diagnosis for this other than the Rod knock?

 

[tekdeus]

A stethescope is your friend.

 

[rakkasan]

Alright, well I just checked, it definitley does make the sound when free revving.

It's still in that same RPM range.

It sounds more like a jingle than a knock though, like something is rattling around in my tranny. But I don't see how it could be tranny related if it's only in that certain RPM range...

Given this, any possible other diagnosis for this other than the Rod knock?

Tranny knock? If it's coming from the tranny, it's not rod knock...

 

[starscream5000]

If you press in the clutch, does the noise stop? Try reving with the clutch pedal on the floor and see if it makes the noise...

 

[6o4turbo]

Still getting the noise when the clutch is in.

It definitley seems to fit the profile of rodknock. However, it's more of a rattle or jingle than knock.

It's very hard to pinpoint where the sound is coming from, between my exaust, electric fan, and injectors it's drown out pretty well.

Can anyone think of what this could be, OTHER than rodknock?

 

[starscream5000]

Throw out bearing? Pilot bearing? Low tranny fluid?

 

[jdub]

I got a kind of rattle at 2000 rpm for a while. Turned out it was my downpipe against the tranny support...I wasn't using the brace for the DP that attaches to the tranny toward the engine. I but a big radiator clamp around the DP to the brace and no more rattle.

 

[tekdeus]

This could be it. Try bumping your exhaust to see if it rattles against something.

I got a kind of rattle at 2000 rpm for a while. Turned out it was my downpipe against the tranny support...I wasn't using the brace for the DP that attaches to the tranny toward the engine. I but a big radiator clamp around the DP to the brace and no more rattle.