[hunterstein555]

So I've been having a rough idle issue on a new-to-me '99 9-3 convertible. There's also a bit of blue smoke coming out of the exhaust. I would also like to mention the previous owner went 10k miles without an oil change

Turning on the A/C would nearly cause it to stall, coming to a stop it would idle rough for a second and nearly stall and then normalize

I started by replacing the plugs, DIC, vacuum hoses, air filter, new belt, currently running chevron techron and gonna change the oil (again) after the current tank. I also didn't change the oil filter the first time I changed the oil filter so the current filter is 10k+ miles without a change :yikes:

Didn't fix it so I opened up the throttle body and cleaned it out with CRC. It looks like there might be oil in there? Here are pictures

https://imgur.com/a/mu6tfRA

I then took out the IAC and threw a ton of WD40 and CRC in there too

Took it for a drive and no luck. 10 minutes later, the problem went away. Running smooth now

My concern now is where is the oil coming from, and it's probably going to continue and clog up the IAC again. I think the only place the oil could come from is the turbo, correct?

The turbo looks to be in bad shape - the lines underneath are pretty rusty (but I can't see any leaks), I can't get up to full boost (no CEL's), but it doesn't seem that the smoke from the tailpipe is proportional to the boost I get. It usually just comes out randomly

My car is not an SE so it has the LPT turbo I think

So what does this mean? Is the turbo leaking internally? I'm thinking the lack of full boost may be unrelated to the smoke

Also, where is the BPC valve on these T5's? I didn't see it at first glance

Thanks a bunch in advance!

 

[Mimmi]

My car is not an SE so it has the LPT turbo I think

So what does that mean? I'm thinking the lack of full boost may be unrelated to the smoke

Also, where is the BPC valve on these T5's? I didn't see it at first glance

LPT is Low Boost Turbo.
T5 lpt do not have BPC valve, compressor and wastegate are connected with single hose. So it is running base boost only.

 

[hunterstein555]

LPT is Low Boost Turbo.
T5 lpt do not have BPC valve, compressor and wastegate are connected with single hose. So it is running base boost only.

Ohhhh

I thought there was a BPC valve specific to T5's or something

So I should never expect the boost gauge to go more then halfway? I thought it would go up to right before the red line

My 02 9-5 has the LPT but it still has a BPC valve (T7 obviously) and goes up to the redline so that's why I was confused

Anyways! Now I have to figure out the oil problem

 

[jvanabra]

AFAIK we did not get LPT 9-3s... only 185hp and 205hp, and both are full pressure. You should have a BPC on your "S" 9-3.

Some oil in the intake system is normal on anything but a brand new car.

 

[hunterstein555]

AFAIK we did not get LPT 9-3s... only 185hp and 205hp, and both are full pressure. You should have a BPC on your "S" 9-3.

Some oil in the intake system is normal on anything but a brand new car.

But smoke out of the exhaust too? It smells like burning oil and it's unpleasant, and it's clogging up the IAC/throttle causing rough idle

 

[jvanabra]

No, no smoke. But with turbos oil in the intake and smoke from the exhaust are not necessarily related.

 

[lms]

Could be the turbo, rings, valve stem seals. Get the compression gauge out and check that. Then, if you have a leak-down tester, give that a shot. You need to change the filter asap. Pull one of the IC hoses off after the turbo/ic. Wrap your finger with a thin white rag and rub it around inside of pipe. If there is an excessive amount of oil, then most likely the turbo seals are shot and you have found your problem (hopefully).

 

[hunterstein555]

Compression numbers were ginormous, 200-210 across all cylinders. I was pretty surprised, as I've never seen anyone mention anything above 180, but I also heard the B204 engines were particularly strong

Yes, I bought a cheap fram filter to put on, and my plan is then to run the chevron completely through, then change the oil filter (and oil) with a quality one

Thanks, didn't think of checking the intercooler. Probably smartest to check the hose directly out of the turbo, way down on the passenger side, correct?

 

[lms]

Compression numbers were ginormous, 200-210 across all cylinders. I was pretty surprised, as I've never seen anyone mention anything above 180, but I also heard the B204 engines were particularly strong

Yes, I bought a cheap fram filter to put on, and my plan is then to run the chevron completely through, then change the oil filter (and oil) with a quality one

Thanks, didn't think of checking the intercooler. Probably smartest to check the hose directly out of the turbo, way down on the passenger side, correct?

Yes, check delivery pipe.

 

[hunterstein555]

Btw my car does indeed have a BPC valve, with the middle hose unplugged. Hopefully this brings some boost back

I've also learned that all U.S. T5 models have the HOT turbo, just the SE is tuned to 205 HP

I'll check the IC hose, just replaced the filter

 

[Doug]

If those TB pics were before you cleaned it, they looked pretty clean to me. I've seen some with what looks like food burnt onto oven trays, on the side of the barrel.

Doug

 

[hunterstein555]

I also just happened to notice the car has no catalytic converter

Lol

Obviously this would make a smell, but would it cause any smoke to come out?

 

[Boxer-Moto]

Btw my car does indeed have a BPC valve, with the middle hose unplugged. Hopefully this brings some boost back

I've also learned that all U.S. T5 models have the HOT turbo, just the SE is tuned to 205 HP

I'll check the IC hose, just replaced the filter

This isn't quite accurate...

The two liter T5 cars all have the same Garret T25 turbo. BUT...only some 1999 9-3s have ECUs that request more boost...which, combined with the cross-flow IC (unique to the '99 HOTs in T5 world), gives 200hp (not 205).

The intercooler is the easiest visual cue to spot an HOT T5.

IOW, the turbo by itself is not high output...it's the ECU's programming that makes it so.

 

[hunterstein555]

This isn't quite accurate...

The two liter T5 cars all have the same Garret T25 turbo. BUT...only some 1999 9-3s have ECUs that request more boost...which, combined with the cross-flow IC (unique to the '99 HOTs in T5 world), gives 200hp (not 205).

The intercooler is the easiest visual cue to spot an HOT T5.

IOW, the turbo by itself is not high output...it's the ECU's programming that makes it so.

Gotcha, thanks for the info!

 

[jvanabra]

Also, double check that cat statement... no cat would result in an instant CEL, unless someone also reprogrammed the ECM to eliminate cat diagnostics.

 

[hunterstein555]

I'll check again but it really just looked like a straight pipe right up to the turbo

 

[hunterstein555]

Just as an update, the car definitely doesn't have a cat. No CEL, so I don't know what that means. Maybe someone can provide some insight to that, and what I should look out for

Not only that, it's pretty much straight piped the whole way through. It has 2.5" or 3" pipe that gradually gets smaller from the turbo down to about the middle of the car, where it meets a factory pipe. There's a flex pipe there, then it goes to the exhaust tip, where there's some sort of muffler right before it

Also, most of this **** has been tack welded

I guess I would be less annoyed if whatever clown that did all of this didn't put a decal for their "Custom exhaust shop" on the inner side of the passenger door. Lol

Anyway, this has gotten a little off topic. I noticed that there's a couple oil leaks coming from the passenger side of the car, and around the pan. It also seems the radiator is leaking a small amount of coolant. So, I will be pinpointing these leaks, and looking in to replacing this Frankenstein of an exhaust, and then I will come back to the issue of oil in the intake

 

[jakejm79]

This isn't quite accurate...

The two liter T5 cars all have the same Garret T25 turbo. BUT...only some 1999 9-3s have ECUs that request more boost...which, combined with the cross-flow IC (unique to the '99 HOTs in T5 world), gives 200hp (not 205).

The intercooler is the easiest visual cue to spot an HOT T5.

IOW, the turbo by itself is not high output...it's the ECU's programming that makes it so.

Correct, it was also limited to SE manual transmission cars, and mostly ones later in the 1999 model year production run at that.