Uh Oh!

I had the boost brought up to about 18psi on my 92 Dec WRX and noticed big performance increases, however I have developed a gravelly/tinny noise like small stones in a metal cylinder when I rev over 3000rpm.

Any ideas?

I hope is isn't melted pistons or turbo problems.

It is not a LOUD loud noise but it is like a bearing that doesn't fit well (loose).

RSVP ASAP

Stuey

 

I'm sorry to say that this sounds very much like your engine is knocking or detonating due to the boost. I assume that you did not have fueling and timeing altered to suit? Your car, MY92, will be particularly sensitive to this .. the earlier the engine the less tolerant they seem to be for some reason, especially as its a WRX and not an STi spec.

Get the boost lowered pdq !!! before it goes bang very loudly, seriously, you will certainly weld rings or melt a piston if its not reduced immediately.

As a matter of interest how was the boost increased and by whom ? The info may enable some suggestions to be made.

If it was a tuning company take it back and complain !!! They are going to cost you alot of money if its not sorted.

Bob

 

I dont want to question the suggestion above but I have an idea that it might be a cracked exhaust heat shield , I had exactly the same noise on my 94MY, in fact I used the same description as you when I took it to the dealer, that it sounded like driving through gravel.
The noise only appeared at 3500 rpm on acceleration but could be heard again as the revs dropped back through 3500 on overrun.
Apparently its a very common problem on earlier turbos, heat shields tend to fracture when very hot and then are suddenly cooled by driving through a puddle or the like.
This problem was sorted on later models.
I hope it is this and not over boost problems
anyway good luck.
p.s Have you ever heard a "Rainmaker" sort of an instrument made from a cactus with rice grains inside? Sounded a bit like one of those. all technical stuff eh!

[This message has been edited by Moz (edited 04-10-1999).]

 

It WAS exhaust guard but I asked them to remove performance modification. They charged me £10 to re-fit the guard which they said had cracked by a bolt. They had to re-drill a hole and refit a new nut and bolt. They said that it was up to me if I wanted to get a replacement but this should last me until I get one.

FYI - The car is now much slower without the modification :-(

Here are photo's anyway

 

Moz,

Not only that but when the revs going down, esp. between 2500-2900, I get a resonating metal vibration noise. This also occurs when stationery and revs kept at 2700-2800rpm.

The garage are having a look at it today for me.

Yes guys, they are specialists and tune many of these Jap Imports.

I will post their verdict and ask how they brought the boost up. However when I asked them the same question last week they wouldn't tell me, doh!

 

Original post said this occured above 3000 rpm and that only started when boost was turned up. If it occurs at 2000-3000 then I think heat shield could be culprit. When mine went it wrattled in any gear at any speed at any throttle setting in that rev range. The cost of the heat shield should be £47 plus vat and it should take no more than 30 mins labour to fit.

 

I think I may have the same problem. Do you notice the rattling sound when changing gear after farily hard acceleration ?

Martin

 

If I rev to 3100-3200 then change gear the revs drop to 2600+ then they pick up and it makes the noise. As I said I will be posting information on this asap. I have a digital camera so I will try to take some photos of the said problem. It would have been nice to have listened to it but I don't have recording facilities yet!

I will keep you posted!!!

Stuey

;-)

 

Can you just remove the shield and be done with it? Or will some of that heat blanket stuff you can get from Halfords do in its place? Mine seems to rattle along the entire length of shield and I have had enough of just living with it !!

 

Could the noise be heard when stood outside the car?

The reason I ask is because I've got a similar noise but it can only be heard from inside with the windows up. Nothing when stood with my head under the bonnet listening for it.

 

I could hear it outside as well.

Stu