Rattling noise by LH Turbo

[actwon]

All,

I have attached a sound bite. It sounds like something is rattling in the turbo or my tranny/clutch. The car moves when I put it in gear with no abnormal noises. So, I suspect turbo.

I do not hear the rattling while it is idling, but when I throttle it to 2 grand and above, I hear it on the increase and decrease of RPMs. The noise is coming from the LH rear of the car, halfway to the rear wheel. Any ideas? Thanks.

Lotus_Rattling_Noise.wav

[outtamyway]

All,

I have attached a sound bite. It sounds like something is rattling in the turbo or my tranny/clutch. The car moves when I put it in gear with no abnormal noises. So, I suspect turbo.

I do not hear the rattling while it is idling, but when I throttle it to 2 grand and above, I hear it on the increase and decrease of RPMs. The noise is coming from the LH rear of the car, halfway to the rear wheel. Any ideas? Thanks.

My guess would be either the cat or heat shield. In my case it was the cat on my '01 with 6k miles. Either should be covered by the emission warranty. Easy to tell if it's the cat, simply give it a good rap with your hand and you will hear the guts rattling. You might also get a lean left bank or similar CEL/code.

[actwon]

My guess would be either the cat or heat shield. In my case it was the cat on my '01 with 6k miles. Either should be covered by the emission warranty. Easy to tell if it's the cat, simply give it a good rap with your hand and you will hear the guts rattling. You might also get a lean left bank or similar CEL/code.

Outtamyway,

I'm looking into the heat shield. See, if it's that uy (I hope so). I don't get CEL codes (Johan's ECU). I will tap the cat though and see if it's that guy.

Thanks!

[Rgardner01]

You may not get a CEL code even if its a CAT. I had one going loose and the other was missing half inside. The original ECU Chip threw up a CEL and Lotus replaced my O2 sensor. I went on with my life and later installed a Johan ECU chip a few hundred miles later. It is to my understanding this chip does not check for cat operation, it only checks for the sensor presence so it will not throw up a CEL. To make a long sotry short I had an annoying rattle at idle. After tearing the exhaust off, hollowing out the cats or what was left its all gone. I also suspect some of my exhaust mounts where a little loose too.

.[quote name='actwon' date='Sep 24 2007, 08:06 PM' post='124897'

Outtamyway,

I'm looking into the heat shield. See, if it's that uy (I hope so). I don't get CEL codes (Johan's ECU). I will tap the cat though and see if it's that guy.

Thanks!

[mike_sekinger]

All,

I have attached a sound bite. It sounds like something is rattling in the turbo or my tranny/clutch. The car moves when I put it in gear with no abnormal noises. So, I suspect turbo.

I do not hear the rattling while it is idling, but when I throttle it to 2 grand and above, I hear it on the increase and decrease of RPMs. The noise is coming from the LH rear of the car, halfway to the rear wheel. Any ideas? Thanks.

Sounds an awful lot like the exhaust heat shield. They are truly crap quality and regularly split, crack and rattle. R&B in Germany do some much stronger guage replacements, which fit perfectly. Unfortunately, the LH one is a real b@stard to replace in situ. You would need to remove the Aircon compressor to get reasonable access.

Some folks just try to weld them, but they will break again.......

Cheers,

Mike S

[talon]

Im in agreement on the exhaust heat shield. I just had mine replaced after it cracked.

[actwon]

Sounds an awful lot like the exhaust heat shield. They are truly crap quality and regularly split, crack and rattle. R&B in Germany do some much stronger guage replacements, which fit perfectly. Unfortunately, the LH one is a real b@stard to replace in situ. You would need to remove the Aircon compressor to get reasonable access.

Some folks just try to weld them, but they will break again.......

Cheers,

Mike S

Thanks! Yeah, the consensus believes that it is the heat shield. I will try to get at it through the wheel well this evening or tomorrow and remove it. I will let you guys know if it is that. I have spent a lot of cash and put in a lot of time rebuilding this motor (yes, I rebuilt it myself... YIPEE!!!), so I am hoping that the heat shield is the culprit. It's cool to have a resource such as you guys. Thanks.

[actwon]

Sounds an awful lot like the exhaust heat shield. They are truly crap quality and regularly split, crack and rattle. R&B in Germany do some much stronger guage replacements, which fit perfectly. Unfortunately, the LH one is a real b@stard to replace in situ. You would need to remove the Aircon compressor to get reasonable access.

Some folks just try to weld them, but they will break again.......

Cheers,

Mike S

Mike,

So over the weekend I checked my heat shield (it was broken, so I removed it). I pulled off the cat to check for loose debris (found none in the turbo, nor the cat). The car still makes that rattling sound. The rattling noise sounds like chatter from a 6 puck clutch disk.

I drove it on Saturday. It got worse once I hit 40mph. It's loud and very constant. I hate to do this, but seeing though I have no more time to dedicate to this, I must take it to the dealer. I'm thinking a bolt is loose on my clutch. I just don't have the time to unbolt and slide my tranny back to inspect my clutch.

[mike_sekinger]

That is a pain, but I can understand your reasoning.

I had one time with a horrible rev. and temperature related rattle..... looked everywhere... eventually discovered that one of the exhaust couplings was loose.

Are you sure that it is an

[actwon]

That is a pain, but I can understand your reasoning.

I had one time with a horrible rev. and temperature related rattle..... looked everywhere... eventually discovered that one of the exhaust couplings was loose.

Are you sure that it is an

[fmxa]

FWIW my 97 doesn't have this rubber plug either, I was told not to worry about it as they are impossible to find.

[mike_sekinger]

Do you have a rubber insert that goes between the bottom of your tranny and engine block? It's purpose is to keep debris from getting into the bell housing. I tried to order one of these, because my car never had one. I was told that it's not for my car, but it's in the parts manual...

As long as you don

[actwon]

As long as you don

[toyroom]

I lost my bung when the great gearbox knackering went on in January this year. I am told it is not strictlt necessary but it would be nice to have it back. I would check your clutch fluid. One reason for losing your bung is that the clutch slave goes and leaks fluid down the inside of the bellhousing and the fluid rots the rubber causing the bung to shrink and fall out. My clutch slave goes every year (and yes, I replace the master at the same time every time and it makes no difference!) For the sake of $200, I am resigned to replacing the slave and master every time I do the cambelts.