Ca18det turbo issue? Please help

[td610]

Hey, I've got an s13 with a ca swap. I'm getting this screeching noise under boost and I really dont know what to make of it. Made this noise before and then the gasket between the turbo and manifold went so I had a huge exhaust leak for a while and lost a lot of power. Just had the gasket replaced and it drove fine for a day and now I'm getting the same sound.. Running a T-25 turbo with an aftermarket tubular manifold. Could the flange on the manifold be warped? f*** turbo? Last time I checked turbo had minimal shaft play.

[cbh148]

What kind of tubular manifold? Ebay XSpower? I've got one and it's garbage.

[td610]

Not sure on the brand. Will check when I have time. Might just try switching back to the stock manifold and see how the gasket holds up.

[cbh148]

I <3 my stock manifold.

[float_6969]

stock manifold > anything aftermarket up to 300hp.

Are you sure it's not a belt? Screeching noises are usually belt related.

[td610]

stock manifold > anything aftermarket up to 300hp.

Are you sure it's not a belt? Screeching noises are usually belt related.

Yeah I'm pretty sure. The noise only happens under boost. Going to swap the stock manifold back on, change the gasket again and I will post results.

Also thinking about upgrading to a T-28 while I do all this.. If I bolted on a T-28 without changing anything else and still ran stock boost, can I expect to see any significant results?

[boost_boy]

You have a failing gasket between the turbo and manifold. It happens, so it's time to change it. Symptoms: The bolts may have backed-off some, exposing the gasket to brutal exhaust temperatures or it's just getting old. Anyways, good luck changing that.

[Liquid_Neon]

Might i add, that even if u changed the gasket... u may have not correctly locked down the bolts with the tiny metal tabs. when i did my first swap and had the turbo there, i LOST the tabs and my nuts would constantly back off.
I bought 10 gaskets and replaced them every few weeks cause i couldnt find the lock tabs.

lock washers DO NOT WORK. they turn into flat washers

[CA18_nut]

Could the flange on the manifold be warped?

yes, check it with a straightedge and feeler gauge. Also some copper lock nuts might be a good idea