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Silverado OM606 Conversion

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40K views 40 replies 12 participants last post by  Juauchu  
#1 ·
Hello Everyone. I’m new to this, so I hope I don’t annoy anyone with naïve content.

The reason I’m here is that I built a 2002 Silverado 2WD with a turbo diesel OM606 motor off a 99 E300. I posted a short video on YouTube and some people asked me for the build details. I’ll post the video link at the bottom.

My project is a daily driver, built for fuel economy, reliability, comfort, and for use as a work truck when needed. It’s something my wife can drive to pick up the kids or go to the supermarket. So this is not a “superturbo”. I say this in case my project may not make a great deal of sense to some.

General Elements and ($):
• 2002 Chevy Silverado 2WD short (stepside) bed. I wanted white but after many months looking for the truck this is what I found
• OM606 stock engine with stock turbo, alternator, PS pump, AC unit, etc. (approx. $1500)
• DIY OM603 (M) pump with 6mm plungers delivering approx. 75cc, I have a spare 6mm pump that delivers 90cc (approx. $1700).
• Chevy 4L60E transmission (model 1999) with stock cooling hoses.
• EZ-TCU standalone transmission controller ($500)
• Adapter plate (purchased from Bendtsen for under $1K)
• Dakota Digital unit for rpm signal ($50)
• 2.5” intake ($200)
BACKGROUND:
I first found a complete engine with transmission. The seller said the motor had a knock (most likely an injector). Turned out the motor was toast. He helped me with parts so I decided to rebuild it. I actually destroyed the original turbo head and ended up using a non-turbo I found. I kept the non-turbo cams and springs. I may replace those with the turbo ones. But the motor started and idled fine after I completed the rebuild. I replaced two pistons, two rods, crankshaft, etc. Then it took me several months to find a truck. The one I found was in excellent condition so I got it for a great price.

MOTOR & TRANSMISSION:
The transmission adapter plate I found online was made for the 99 4L60E so I picked one up from the salvage yard and rebuilt it (I could not use the exact 2002 4L60e that came with the truck). To control the transmission I bought an EZ-TCU controller. I should have spent a bit more. The unit has been throwing a code although the transmission continues to shift normally. The EZ-TCU needs a TPS. There are standalone TPS kits online. I made my own one. The TCU also needs an RPM signal. Dakota Digital sells a small unit that generates an rpm signal, those rpm units are great. They allow a few options to generate the rpm signal, I used my alternator with the “W” terminal. I actually had to find one at the junk yard. Many diesel alternators already come with that terminal. You can also use the om606 sensor picking up with flywheel to generate an rpm signal. And finally (besides voltage and ground), the TCU needs a signal from the speed sensor at the tail of the 4L60E. The TCU is customizable (I think just made that word up) which is really cool. Look it up.

After having mated the motor and transmission I made the motor mounts. I stated with the stock Silverado mounts and cut them such to weld a flat surface where the stock mounts from the OM606 rest. It’s easy to make motor mounts so I won’t elaborate because my mounts were not the best ever due to my crappy welder. Point is that the stock om606 mounts sit exactly where the stock Chevy motor did. There’s plenty of room in the engine bay, however, this is the position I liked which kept the transmission (drive shaft) at stock position. This motor mount position, however, involved a conflict between the rack and pinion and oil pan. It’s easy to modify or relocate the oil pan well. I kept the stock and initially relocated the rack and pinion. I developed a death wobble (yes, death wobble) so decided to move the rack and pinion back to its original position (then found this was not the cause of my death wobble). Anyway, this meant that I had to notch the rear corner of the oil sump to make room for the rack and pinion. The modification to the oil pan was fairly small so I didn’t mitigate for oil capacity. Kept the stock drive shaft. There will be plenty of space between radiator and fan. I kept the om606 steering pump, alternator, serpentine, etc. Coolant hoses were mostly stock either Chevy or Benz. Kept the Silverado radiator and reservoir set up. I made my own throttle linkage from parts I found at the junk yard. I’m pretty creative but you can imagine it does not look impressive. There are linkages from the 95 E300 (mechanical pump) that will work, no need to make your own. The motor is hard to find but they are available for around $2k. I actually bought a whole car first and right after found the motor and transmission alone. So I still have the car which I’ll save for another project—runs excellent. I made the mistake of not rebuilding the head. I will try it down the line.

FLUIDS:
Speaking of oil and fluids, I kept the stock transmission lines (and radiator), and made custom hoses for oil cooler. I used the OM606 oil cooler. Also made a power steering hose. I will add here that I kept the fuel pick up unit but removed the gal fuel pump. However, I used an external diesel sump and a ½ inch hose from it straight to the lift pump; this to avoid ¼ tank issues and fuel restrictions.

ELECTRICAL:
Kept the Silverado ECU and eliminated any parts of harness obviously not needed like fuel injectors, etc. All my gauges work, Silverado cluster of course. Spliced the speed sensor (purple) wire to share with the TCU but kept the original wire feeding the Chevy ECU and my speedometer works. The stock OM606 temp sensor works. The tachometer…just find the tach wire and hook it to that Dakota Digital unit I mentioned. The EZ-TCU plugs right to the transmission harness. From the junk yard, I picked up an OM603 glow plug relay for my glow plugs. Just wire it to a signal that feeds juice when the ignition switch is turned on, you’ll find plenty; just like your rpm unit and TCU will need juice. The alternator and starter are an easy hook up, the wires are just rerouted.

INJECTION PUMP:
It would be a sin to use an OM606 engine with M-injection pump (om603) with 5.5mm elements; you find many of those on ebay for around $500. I got mine for $70 at the junk yard. You should at least upgrade to 6mm plungers. I swapped them myself. Shops charge around $1500 to swap them because it’s laborious…when you don’t have the right tools. After swapping them I took it to a shop for calibration which normally runs around $300. My pump delivers approx. 75cc, plenty for my needs. I have another 6mm pump that delivers 90cc. If you want more fuel then you can order 7 or 8mm (or more) plunger pumps; this would entail more expensive modifications. A pump with 6mm has plenty of spirit for my light Silverado.

TURBO:
Kept the stock OM606 turbo. I changed its actuator to a boost driven. Twisted the housing a bit to fit the intercooler hoses which were routed to mount the cooler behind the bumper, best place I could find. Kept the om606 intake and intercooler pipe attached to it, which ends near the AC compressor.

SUSPENSION
I lowered the truck 3” in the front and 5 in the back (flip kit). The reason was to make it a bit more aerodynamic…and I like the look. I liked them raise or lowered, nothing stock. After the swap the front suspension bounced too much. I replaced the springs. The om606 motor is supposed to weigh about the same as the 5.3L I removed, but the springs had a different opinion. Ended up rebuilding the entire front end just to make it perfect. The truck is flawless cosmetically, it just needs a polish.

TIME:
Working on my own and in spare time it took me about two months to swap the engine get it running, after I had the engine, transmission, and truck. Dropping the motor is easy. I removed the entire front end, it makes it easier. A helping hand would be real nice here and there to muscle things around but with patience and creativity it’s doable by your lonesome. It takes a bit longer (as a novice) to fine tune things here and there. When you know what you’re doing from the get-go, it’s a lot faster. I could do this same project again in about 2 weeks, full time and with all the parts ready.

SUMMARY:
This project is not really that hard. It was a lot of work for me because I got too ambitious and ended up rebuilding engine, transmission, and injection pump. Something I’d never done before and have limited skills, tools and money. My project is still fairly clean and presentable. I will still have wiring to clean up. I will figure out a way to post some pictures. Again, there’s tons of room under the hood for this conversion. A Chevy with a power steering box may present more conflicts, so I decided that the rack and pinion might be easier to work around. I cut a few corners here and there but all still worked out real well. I needed to save as much as I could. I had a $10K budget. So far I’ve spent a little over $8K, but that’s including work like lowering it and front suspension rebuild which was not considered initially. It would have been cheaper if I didn’t rebuild motor and transmission, and if I used the 722.6 transmission with standalone controller. The more expensive parts are motor, adaptor plate, and injection pump.

RESULTS:
The truck glides real nice on the freeway and has plenty of acceleration, maybe comparable or better than the Chevy 4.3L V6, or comparable to the 99 E300. My Silverado is actually slightly lighter than the donor E300. I’ve put about 1500 miles on the motor and is returning 30mpg hwy. I hope to get it near 35mpg with a few things I still have to tweak. Sometime later I’ll test it for top speed, but it feels like I should do 120mph easy. We’ll see. I still have to make hoses for my AC, but I got to fine tune a few other things first.

VIDEO:
You'll find a YouTube video under "Silverado 1500 with OM606 Diesel Engine Conversion"
 
#31 ·
Hey Diesel Noob, sorry I just noticed your post.

Actually I do have updates, there probably hasn't been a day since I originally started this thread that I haven't done something on my truck. So there's been lots of suspension work, etc., etc., although the most significant progress took place just recently and it was related to performance. From the beginning the truck was lacking acceleration in the lower end. It appeared that I would only get useful boost past 3k rpm, however, for daily driving in congested city traffic, it was very annoying. I spent lots of time and money trying different torque converters (1300, 1600, and 2200 stalls), and different turbos among many other things.

Again, I had started with the stock kkk14 turbo. Then I tried a TD04HL but saw no significant difference. Then I tried a GT23V off the OM648, which is what I currently have now. This turbo definitely spooled faster yet my truck wasn't performing the way I thought it should. I was about to fit my mechanical pump with 7.5mm elements but instead decided to try a stock EDC pump (6mm) with Baldur's DSL1. HUGE IMPROVEMENT!!! My truck finally drove awesome. I just switched to the EDC IP a few weeks ago, I'm still fine-tuning things but from day one the truck ran terrific. Even with just a 4-speed transmission my truck performs better than the stock W210 E300. I will continue to fine tune fuel and boost with the standalone ecu, however, any gains from here on should be small. At this point I pretty much want to optimize fuel economy, which I should get to in the next couple weeks.

Now with a more precise RPM reading (my previous rpm unit was deceiving me, it was my fault), I'm finding out that my rpm's are around 2000 at 70 mph. That rpm is a bit low. I currently have a 3.73 rear end and I want to switch to a 4.1, hopefully in the next couple months.

The other major problem I was dealing with when I first started this thread was the mysterious death wobble. I have replaced just about every suspension part there is. Eventually I managed to control the wobble, I can say I haven't had it in several months, however, I know the problem is still there. At certain highway speeds, around 50 mpg, the problem (wobble) is triggered however it's controlled instantly. A good alignment shop set my caster around 1 degree. It's supposed to be something around 3.5 or so I believe, but that spec caster makes my wobble way worse. I'm not going to give up on this, I'll figure it out sooner or later. I'll start by repositioning the motor and re-doing the mounts with an OM648 oil pan I just got.

I will be posting another video real soon, for sure a drive along one.
 
#33 ·
I do, in fact, when the problems fist started my wheels and suspnsion were all stock. A couple months after I finished the swap, one day out of the clear blue it started wobbling bad on the freeway. I thought something had come loose but no, I even struggled some to get back home just a few mile away, had to keep it under 40mph. At that point I started replacing just about every suspension part. Eventually I lowered the truck and problem continued. I’v also struggled to get it alighned, as if I had wrecked it but it’s never been hit. I had the chasis checked and it was good. It also bounces more than normal (on healthy, heavy duty schocks). I’ve tried lots of wheels and schocks, new and of good quality. Sort of seems as if some structural member is pre-loaded, stores energy (kinetic I think), to a point that gets hard to dampen by schocks. I checked the chasis thoroughly for cracks, etc. Something else, the first few weeks after completing the swap, the front end bounced excessively; sometimes I had to stop the truck to kill the bounce, the reason is that I had not yet replaced the crossmember that seems to absorb most of front wheel loading. I have wondered if I bent the chasis, but then again it checked fine. Also re-torqued all bushings to see they don’t have a preload manisfesting an inability to dampen energy.
 
#41 ·
Hi guys, i am a bit late.

i am from Germany and i think the om 605/606 are the greatest engines ever! So thank you for this thread.
A bit advice from me for a swap.
Always take baldurs ecu and keep the electronic pump. Keep the merc trans not to waste torque to shifts at wrong rpm! Change gear ratio to the similar ratio of the merc axle.

the Om606 goes as hell with original element and turbo. Remember the Om606 has 177 german DIN hp thats pretty similar to a 260 sae hp gm gas engine and it should easily make 45 mpg in the silverado on highway.

thanks and save fuel 😂