Well the intitial question explains it all, exactly what would I need to do a compression test on a '67 200D? I am looking at purchasing one and I wanted to know exactly what I would need so I could just do it there. Can I just use a gas compression tester? What size fittings are the GPs? Should I do it warm or cold? Heard both ways. I did a search and saw someone's "poor man's compression test." It involved using no guages on a vintage 190D which is pretty much the same as this. Said that once the engine started to warm up you shut if off then just start cranking for a few minutes until it built up compression and fired.
Is it really good to crank an engine for a couple minutes? And while the engine is cranking, aren't the GP's lit anyways?
Thanks
David

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2000 Honda Accord V6 137k miles

1972 300SEL 4.5 98k miles

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You cant exactly do it there ... but if you want to try, you will need:

17mm wrench
1 1/16" (27mm) long Socket and Socket Wrench
Phillips Screw Driver
4 Shop Rags
Diesel Compression Tester with proper injector fitting.
Jumper Cables

Take the car for a test drive and get it nice and hot. You will want to test the compression while hot, as it is a better indication of the running condition of the vehicle than a cold test.

Unscrew the clamp for the clear, in-line fuel filter leading to the IP. This will cut the fuel source to the motor to prevent it from starting during the turn-over process.

Use the 17mm wrench to unscrew the hard fuel lines leading from the injection pump to the fuel injectors. Disconnect all four from the injectors, and loosen them at the injection pump. Slide the lines from directly over the injectors, so you can remove them.

Remove all four injectors using the long socket. Stuff the rags into each injector hole to prevent debris from getting into the pre-chambers.

Attach jumpers to the tested car from a running vehicle. This will keep the car charged during the many starter turnovers you will need to gather enough data.

Now simply screw the compression tester adaptor (specific to each injector ... verify you have the correct adaptor size.) into one of the injector holes. Attach the compression tester (which is just a hose and guage) to the adaptor. Turn the motor over 7 - 12 times. Take a reading, release pressure, and try again. Take a couple readings from each cylinder. You should be right around 315psi for each cylinder, with no more than 10-12% between the four.

Note on diesel compression testers: Conisdering diesels operate at a considerably higher compression ratio than gas motors, a diesel compression tester is accurate to a much higher PSI, usually 1000. Also, diesel fuel injectors vary in size from spark plugs, so a special adaptor must be used. Moral: A diesel compression tester is very different from a gasoline compression tester.

Good luck, Cassidy

I forgot to add that I think this is a pretty bad idea.

If I were a seller, I would tell anyone who brough compression testing tools to my house for a test drive to f*&k off.

Mabye you will be lucky and he will let you check it out...

Cassidy

David,

Regardless of how little you pay for a 200D these days you could end up with a white elephant. Do you know what a white elephant is? Over there in Africa or Asia someplace white elephants are sacred and are not allowed to be put to work. If you really have a grudge against someone, you give them a white elephant as a gift which they are obliged to graciously accept. Now they are responsible for the care of an expensive animal that they can't use. I'm suggesting you spend a few bucks to have the car checked by a shop that knows those cars, so you don't end up with a car that you don't know what to do with. Good luck.

Cassidy,

It is perfectly acceptable to have a car checked out before purchase. Not everyone is as honest as you. You are honest aren't you? If you wouldn't let me check your car I'd let you keep it.


Peter

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Auto Zentral Ltd.

Sure, I am very honest... check my critical jag listing for a reference:

http://www.190revolution.net/xjs/

The final buyer actually said that I was hard on the car. Whatever the case, honesty has nothing to do with it.

I simply would not let someone perform such a complex operation on my vehicle in my driveway because ... frankly, I dont trust anyones mechanical abilities untill they are demonstrated to me. I wouldnt want to learn the hard way that they didnt know what they are doing.

For instance, if the IP fuel source is not disconnected, turning the car over would squirt hot diesel all over a hot engine. Rather dangerous.

If I were you David, I would take the car to a reputable mechanic for a compression test. Also have them check the condition of the shocks, springs, brakes, engine accesories and belts, wheel bearings, flex discs, cam wear, etc. It is worth $250 for a very thourogh inspection, because as I learned, $250 doesnt get you very much in repairs.

Cassidy,

Now that you've explained your reasoning I concur, and I think we are on the same page. I would also be reluctant to have a novice mess with my car especially if he blew out an ignition module on my 560 trying to check compression. Speaking of 190s, I have an 89 190E 2.6 that runs great. I could drive it across country if it weren't for the two crushed doors on the pass side. I'm looking for another car to transplant the engine or sell the engine to someone. Do you know anybody in the S.F. bay area?

Peter

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Auto Zentral Ltd.

No Autozen, I don't know any one in particular.

I run www.190Revolution.net, a forum much like this for 190s exclusivly. I recommend you head over there and post a for sale ad in the classifieds. I would say there are a good 60+ members in the Cali area who might be interested.

Take it easy, Cassidy