I have an '86 XT Turbo running 9.5:1 compression, and I think about 8 pounds of boost. It is currently not intercooled.

 

My engine makes an odd rattling noise on the drivers side when I accelerate. USUALLY, it only makes this sound when I accelerate quickly. At first I thought it was the shroud, because its only being held on by one bolt. But the rattle isn't metalic-y enough to be the shroud and the sound is coming from the wrong side of the engine. My brother thinks my engine is detinating, but it's been doing it almost since I got this car (August?) and if that were the case, I'm pretty sure my engine would be toast by now.

 

Anyone have any ideas of what this could be? Is it just "old Subaru sound," or something more serious?

Would a "tick" more describe your noise? Or is it more a rattle?

Might want to pop the valve cover on that side and have a look.But like Rick said it might be detonation.Try running some seafoam through it and see if it frees it up at all.You may have lifter starting to make noise.......Or your car just wants a peanut butter sandwich really bad.

It's hard to explain... It's kind of like a tick and a rattle together. I don't know. A tick-ish Rattle-y sound....

Under accelleration would indicate ping or detonation. What grade gas do you run? Try higher grade gas and timing adjustments. You should be able to adjust some of the ping away and better gas should help as well. Stay away from AM/PM fuels for performance and mileage.

I would say try higher grade fuel.For me I have found Bradly Petroleum and Sinclair gas to be good quality and it's home based here in the US.

Agreed - 9.5:1 with 8psi boost and no intercooler is gonna need high octane gas.

I would say try higher grade fuel.For me I have found Bradly Petroleum and Sinclair gas to be good quality and it's home based here in the US.

i tend to prefer diamond shamrock but avoid shell at all cost i put 85 octane shell in my truck and it ran like it was out of gas the whole way through the tank

91 octane is the highest I've seen in my area... and that's what I run.

 

Most people I've spoken to seem to think it's pinging, so we're going to knock the timing back a bit and see what happens.

I don't mean to thread hijack... (ok, maybe I do), but I am also having an odd noise from the engine of my XT, it's a different noise.

 

I've noticed a couple times when the engine is cold and I'm accelerating, that there is a whoosh/whine noise from the engine bay, starting about 3k RPM, and does not go away until the temp gauge reads about half (fully warmed). It does not happen all the time, the only thing I can say is that it is consistently linked to RPM, and it sounds like a BOV that's stuck open (mind you, this car is non-turbo)..

 

any clue? it's kinda disconcerting...

It's more of a ripping clacking sound. I advanced the timing too far on the brat, and got the SAME EXACT NOISE!!!!!!!!

 

 

Listen now, and save your headaches for later!!!!!!!!!!!!!!!

 

INTERCOOLER!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

TIMING!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

Also, learn how to spell these things on XT6.net....study now with my 8 week program, and also learn how to spell "cold start injector" LOL

 

Rex Kwando!!!!!

 

er-Rick

Well my 86 Turbo has had all the same noises. QMAN hit it on the head. Run better gas and bump timing back a little. I run all my cars about 5degrees advanced and if I pass that I can really hear it. Most cars seem to run better a little advanced.

 

Have also noticed since it got down to the single numbers abouve zero here now that I have to let it warm up before I try to leave. I remember Austin telling me to wait until I have a bar showing on the gauge before going with it. Sofar that seems to worm. So warm them up guys.

Ever- does your noise sound like running water? My XT does that.... it's a coolant issue. Check to make sure you have enough coolant, then check all your hoses and make sure they're not cracked.

 

Thanks, RexKwando. KBD said he'd buy me an intercooler, so that's what I'm waiting for. I'll get him to knock the timing back for me in the mean time, though.

 

Uh, yeah.

Ever- does your noise sound like running water? My XT does that.... it's a coolant issue. Check to make sure you have enough coolant, then check all your hoses and make sure they're not cracked.

 

No, though there is an occasional gurgling/water noise, so I suppose checking the coolant would be a good plan.

 

I don't think the rushing air noise is related to that.