Unpleasant growl at low RPM (turbo)

C

completeferrus

New Member
This is the 94 2.8 intercooled turbo diesel.

I have uploaded a short YouTube video (link below) so you can get an idea what it sounds like, but basically the right side of the engine (my old mechanic was confident it was the turbo compressor) growls consistently between 1000 and 1500 rpm. Above that the engine bay is quiet and runs smooth. It's been like that since I bought it a few years ago, and it gets quieter sometimes but generally annoying in the wintertime.

He told me it wasn't worth fixing, that I would have to rebuild the whole turbo. The EGR was deleted on this one and I imagine that could have had some negative effect on the compressor. I'm wondering if there is anything else I can do, any thing I can tweak or replace that wouldn't cost 4 grand. It doesn't seem to affect performance that I can tell and it hasn't been getting worse, it's just a bit of an ugly sound. Also, when I first bought the Delica the turbo had seized! which just took a little tap with a mallet to fix, but it might be related to the fact that it had been run before I got it with a seized turbo!

I cleaned out the dirty intercooler last year hoping it might help move things a little smoother but I didn't notice any difference in the sound.

Any advice from you turbo diesel heads would be super appreciated, thanks!

Engine sounds:

 
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The EGR delete did not contribute. If it had previously seized I would guess it's bad... but it doesn't sound like something I would expect. You can check the turbine for play easily enough. A new CHRA for the turbo should cost a lot less than $4k.
 
That sounds like a loose heat shield or similar to me. Or perhaps a loose hose clamp on a turbo hose.

It doesn't sound like a noise the spinny bits of a turbo are capable of making.
 
Growlerbearnz said:
That sounds like a loose heat shield or similar to me. Or perhaps a loose hose clamp on a turbo hose.

It doesn't sound like a noise the spinny bits of a turbo are capable of making.
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That was my thought as well, muffler heat shield against the body... But I've never heard of anyone running a turbo that had previously seized; I've got no idea what kind of noises that might cause.
 
sk66 said:
That was my thought as well, muffler heat shield against the body... But I've never heard of anyone running a turbo that had previously seized; I've got no idea what kind of noises that might cause.
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Thank you so much for the input to the both of you! I've had a poke around and wiggled and tapped everything I could, and now I am pretty confident it wasn't the turbo at all, though there still might be some possibility of play in the turbine as I haven't been able to check that yet.

A good part of the noise turned out to be from the large plastic tube outside the filter box heading into the sidewall (I'm assuming cabin air intake), which was jiggling about 1mm along its axis, probably due to some old rubber gasket. There is still a little bit of noise so I will poke around the heat shield to see if that is vibrating as well. Amazing that I drove this thing for years thinking that I just had to live with this horrible noise haha.

By the way, about the seized turbo, when I first bought it I noticed it was really struggling uphill, but this being my first car I didn't know any better. When I went to the mechanic he told me that he just took a mallet to the turbo and it started working. I said thanks. Instant increase in power. Usually costs more for something like that!
 
I had similar sound on my l400. Check all the bolts around the front fenders and cowl area with the hood open. Sounds to me like sheet metal vibration in front of dash
 
My concern with a previously-seized turbo with too much play is that it might just explode while making high boost one day. Slight play can snowball very quickly.
An exploded turbo fills the engine with metal particles. This is not good for an engine.

I'd replace the turbo with a new one, just for peace of mind.
 
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