3-Series (E21, E30)Chat relating to the BMW 3-Series from 1975-1983 and 1984-1991 line. Specific models: BMW 315, BMW 316, BMW 318, BMW 318i, BMW 320/4, BMW 320i, BMW 320/6, BMW 323i, BMW 320i. E30 Family models include: BMW 325e, BMW 325i, BMW 325is, BMW 325ix.
new to the forum. picked up a 90 318is with a partially completed budget turbo install. working on things one step at a time, but it's definitely tough to pick things up mid-stream. goal is mild boost, keep stock engine and clutch. I've picked up a limited slip for the car as well to replace the open diff it came with.
near as I can tell the engine is solid, turbo functions (mitsubishi turbo off of a miata kit). there's a massive vacuum leak somewhere which I haven't been able to chase down. when I picked the car up there was no exhaust on it, just a flex pipe attached to the turbo flange.. I had a custom exhaust system put in with 2.5" pipe, magnaflow cat and muffler. O2 sensor is installed. there is a BEGI RRFPR installed, mustang injectors, stock ECU.
there's a nasty oil leak somewhere as well - probably the return oil line on the turbo. the intercooler piping kept slipping apart, but I think I've fixed that now.
on the plus side, body and interior are in pretty decent shape after several weeks of effort, engine itself appears solid.
Looking forward to your help, advice etc as we get this beast tuned in.
connected a vacuum gauge - 0 reading at closed throttle, about 15" hg when engine at 2500 rpm or so. absolutely will not idle right now, cold engine or hot.
when I got it back from the exhaust guy it was running a bit rich but not too bad. plenty of power. of course when the intercooler piping disconnected that all went to crud. everything's back together now, car was driven for about 10 miles / 20 minutes to get the ECU tuned in, heel and toeing all the way to keep it from stalling. huge cloud of black smoke as throttle closes, clearly running way rich. seems to have leaned out a bit now. also looked like some oil smoke when throttling off (like valve guides leaking oil). this is a boosted motor though so don't really think the valve guides an issue. least of my worries at this point anyway.
just want to get this thing to idle properly. we'll take it one step at a time from there.
given the lack of responses I posted a thread over at e30tech. additional info:
turbo is a mitsubishi TD04H with a 6 vane compressor wheel. don't know the compressor wheel size. one of the folks over there suggested I look into a rebuild kit given the oil leaks. the turbo has very little end play and spins freely, so no real mechanical issues to speak of. not sure how I could have bad turbo bearing seals but gonna try a rebuild to find out if that fixes things.
otherwise the next area to investigate is probably the oil feed line (maybe there's not enough restriction / too much oil being fed to turbo bearing. also gonna look at the return line. fitting in the drain pan is a bit low. fitting ID is about 1/2" but one of the folks at e30tech has a 3/4" oversized setup - in effect the large pipe is a temp reservoir for turbo oil should the oil pan port be backed up.
yeah my head's in the same place - haven't done the compression test though - trip to harbor freight in the cards...
just pulled the turbo. no oil in the exhaust manifold at all, so it's definitely the turbo's oil delivery system that's the problem. I suppose you could argue that the turbo just fried, but it appears to be mechanically sound. what I don't get is how the oil gets past the turbo bearing seals if the "mechanically sound" assessment is true.
I found a TD04H repair kit on ebay that included parts for both flatback and superback compression wheels. so I'll follow the turbo repair guide I found online.
I'm also going to take a look at the return line to make sure there's no blockage in it. if I need to I'll pull the pan and relocate the return line fitting as it's pretty obviously mounted low / below the oil line.
once this oil thing is sorted I can move on to the air/fuel mix, no idle, vacuum problem etc.
i think the facts support your view. started to take the turbo apart by removing the clamp connecting the intake and exhaust sides.. turbine housing separated from the compressor half without any effort at all. it's pretty sloppy in there - contrary to my earlier post about no end play when I checked it while still mounted in housing and in car. then again it probably needs to rest in the turbine half to spin properly, so I may be reading too much into things.
regardless given the way it came apart, my guess is this thing's been taken apart before.
haven't done the compression test though - trip to harbor freight in the cards...
picked up a nice compression gauge set with detachable hoses. will run the compression test tomorrow, but from what the PO told me I don't expect to find any issues. then again there is some oil fouling in the back cylinder (see the pic earlier in the thread showing the plugs removed)
I've been updating on e30tech, but here's the skinny:
- turns out the turbo's a Greddy TD04H-15G off a miata turbo kit. there was an MHI part number on the intake side of the housing that I had missed, 49189-00640
- I ordered a rebuild kit, spent a day patiently with the CHRA getting it done
- reinstalled the turbo and refitted all the intercooler piping.
started right up. ran the car for a couple of miles, piles and piles of smoke out of the exhaust. original exhaust side turbo leak was still there. didn't check the intake side yet but I suspect the compressor side is leaking oil into the intercooler piping as well.
so bottom line turbo's probably shot. looking for a replace CHRA or turbo.
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