Black smoke, loud noises, low power... Is my turbo bad?

[Ried363]

Please help!

I was driving over the weekend and heard my engine instantly get louder after downshifting.

Here are the symptoms:
- low power
- black smoke on acceleration
- engine sounds more like a tractor (knocking)
- oily turbo (especially around seals)
- cannot hear whistle of turbo at light revs, only at higher speeds when releasing throttle (sounds very faint)
- possible oil consumption (time of problem: oil level was dead center of dipstick between notches; 100 miles later: oil level was 1/4 above the bottom notch on dipstick)

I was able to drive home (nearly 100 miles) without issue.

I plan to remove the turbo this week for inspection and possibly buy a new one on ebay... Any advice would be much appreciated.

Are there any other components which might have malfunctioned and caused this problem?

Also, during the removal process, is it likely that I will have to replace the intake/exhaust manifold gasket?

Thanks for any help!


Ried

1990 (92) Mitsubishi Delica l300

[Growlerbearnz]

Black smoke, loud engine, low power: it's definitely a Delica

Usually turbo failure is either very gradual (a little more smoke in the exhaust, a little less boost), or very, very sudden and quite exciting. The sudden/exciting failures don't usually allow a 100 mile drive home.

If the clattery tractor noise happens at idle as well as at speed, then I'd say it sounds more like your timing belt might have slipped a tooth. Sometimes this happens because the tensioner is loose (but I'd expect it to slip more teeth on a 100 mile drive), sometimes it's because your balance belt breaks, knocks the timing belt off a tooth, and then settles into the bottom of the timing cover to sulk (until you drive over a big bump and it comes out to play again.) The oil consumption can be because of the extra pressure in the engine from the fuel being injected at the wrong time- the same thing that causes the rattly noise.

Before removing the turbo (a pig of a job), I'd remove the top timing cover and have a look around inside with a flashlight for any spare bits of balance belt. If you don't see any, turn the engine until the cam and fuel injection pump pulleys point to their respective timing marks, then look for the timing marks on the lower plastic belt cover- the crank pulley notch should be pointing at the leftmost "T" mark on the belt cover. If any of the timing marks are misaligned you've slipped a tooth.

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[Ried363]

Man! Thank you for this info! I'll tear into it this weekend and find out for sure. The more I think of it, the more your idea seems right. It was on a particularly hard downshift when it happened, and as I believe, all the belts are relatively new and might need to be tensioned. fingers crossed.

[Ried363]

Thank you immensely for the post about skipping teeth on the timing belt. That was the exact problem. I lined everything up,followed your instructions, and fixed the problem without trouble. You've saved me from so much stress and wasted time.

[Growlerbearnz]

Awesome! Glad you're back on the road. And thank you for letting us know how it worked out- it'll help anyone in the future with a similar problem.