installing a turbo in a '84 190d?
 

I was wondering if anyone had any ideas regarding this prospect. The car has a 2.0 liter engine and as far as i can tell, never had a turbo on it, but... A friend of mine told me that the most difficult part of this project would be finding an exhaust manifold that had an outlet to send the exhaust to the turbo. Well, lo and behold, i looked under the hood and realized that it seems the manifold on my car's engine has a square-headed plug threaded into it. This was a grey market car, but i can't think of why this should be the case, other than that perhaps the manifold was replaced at some point with a second hand part--seems unlikely, but what do i know? Anyway, assuming that this manifold is suited for this, can anyone suggest what other modifications i might need to make? Is it worth messing with a used turbo, or can a suitable new one be obtained for a reasonable price? Do i need to find a different intake manifold or replace any other components?

Aaron

'84 190d, daily driver, 4-cyl 5-sp sd trans, converted to WVO, not using up the oil i collect fast enough 'cause it's getting 40/gal!
'83 300td wagon, many issues!
'88 240 volvo st.wagon, 5-sp sd, as good a gasser as ever there was, on permanant loan to my mom.

MB didn't turbocharge the OM601 engine as found in the 190D and 124 200D. Maybe in other applications. There are a number of differences between turbo and non-turbo OM602 and OM603 engines which are 5- and 6-cylinder versions of the same basic design. The biggest visible difference between the turbo and normally aspirated versions of those engines is oil squirters to cool the undersides of the pistons. I'm sure there are differences in materials used as well, and possibly in valve timing. I wonder if the OM601 injection pump has an atmospheric pressure compensation device and if so if it has the range to enrich fuel up to 1 bar over atmospheric pressure. A turbo is useless if there isn't fuel to avail of the extra air.

If you study the US OM603 from 86-91, you'll note that the exhaust manifold and turbo assembly is basically a 4-cylinder design with 2 extra runners in front. The US OM603 from 92-95 is a more efficient design with 2 extra runners in back. So you have some almost plug-n-play choices on the passenger side assuming the 190D engine bay is wide enough. Oddly the OM602, as far as I've read, doesn't use a 4+1 manifold. Does the OM601 have a fitting for turbo lubrication ahead of the block drain plug? If not you'll have to route an oil feed line from the oil filter housing.

IIRC the OM601 air cleaner is in a box on the driver side. The air cleaner is basically the intake plenum from which individual runners extend to the cylinder head. If so you'll need to rework that arrangement because the air filter isn't meant to be fed 1 bar over atmospheric pressure. You might be able to do something with an OM602 or OM603 intake manifold by lopping off the front one or two runners but I think you'll have interference problems with the oil filler cap and/or cam sprocket hump on the valve cover.

For the effort involved, it will be easier and probably cheaper to drop a turbo OM602 into your car, or exchange your car for a 190D 2.5 turbo.

Sixto
87 300D

In addition to the oil squirters, I think the piston heads have special channels cast and/or cut into them to allow the squirted oil to circulate and remove the additional heat that results from turbocharging. Without such things you risk melting a piston. Although it might be possible to retrofit the parts (if you had a machine shop and were willing to tear down the engine), it would definitely be easier, less expensive, and less risky to take Sixto's advice and drop in a 2.5 turbo engine.

There was a turbo 601 used in the 96-03 Vito.

Add an IC and EGT gauge, and as long as the whole system stays within proper operating range you should be ok.