Compression tested my junkyard OM606
Compression tested my junkyard OM606
I posted this in my build thread, but I figured I'd copy it here as well since it's more relevant.
Finally got around to compresion testing my boneyard om606. It didn't go well.
Ended up breaking cylinders 5 and 6 glow plugs. I attempted to extract both without success. So I decided to compresion test 1-4. If they're good I'll keep it and get the machine shop to extract those two glow plugs. If' not I'll bring her back to the scrapyard and keep looking for a good donor.
Well here are my test numbers using the glow plug holes, a spare battery connected to the starter, a battery charger set to 50A on the battery, and a screwdriver to jump the starter. It turned over sooo slow, so I hope that has something to do with the terrible compression numbers. I did not add oil or anything, just screwed my adapter in to the glow plug hole and turned it over.
#1-200psi
#2-220psi
#3-200psi
#4-150psi
I really hate to call this thing toasted, because they're somewhat difficult to get here in the US. This one was dirt cheap, About $300 for the engine and trans. I figure including purchase price, I can rebuild top and bottom end and still not go over $1.5k which is what I'd expect to pay for a wrecked 98-99 w210, or importing a good used engine. I don't have a leak down tester that will fit my glow plug adapter, but I may have to rig something up or at least pull the oil pan and valve cover to see if this thing is even worth salvaging.
Any thoughts, recommendations?
You would try to start and warm up the motor before doing a compression test. Or just try a wet compression test to see if cylinder 4 increases in compression. Could just be a ring not sealing correctly since it hasn't been ran in awhile... suck about the glow plugs
(07-14-2018, 07:12 PM)baldur Yeah you won't get good compression test numbers without a good battery.
(07-14-2018, 08:37 PM)supracrazy You would try to start and warm up the motor before doing a compression test. Or just try a wet compression test to see if cylinder 4 increases in compression. Could just be a ring not sealing correctly since it hasn't been ran in awhile... suck about the glow plugs
(07-14-2018, 07:12 PM)baldur Yeah you won't get good compression test numbers without a good battery.
(07-14-2018, 08:37 PM)supracrazy You would try to start and warm up the motor before doing a compression test. Or just try a wet compression test to see if cylinder 4 increases in compression. Could just be a ring not sealing correctly since it hasn't been ran in awhile... suck about the glow plugs
(07-15-2018, 09:35 AM)Granfatherglock(07-14-2018, 07:12 PM)baldur Yeah you won't get good compression test numbers without a good battery.
It is a good battery, Exide 700CCA AGM.
(07-14-2018, 08:37 PM)supracrazy You would try to start and warm up the motor before doing a compression test. Or just try a wet compression test to see if cylinder 4 increases in compression. Could just be a ring not sealing correctly since it hasn't been ran in awhile... suck about the glow plugs
Thanks, I wish I could warm it up first. I thought about trying to get some water in it and plugging in the block heater, but I doubt the block heater will get it warm enough to make a difference. I'll get wet compression numbers as well.
(07-15-2018, 09:35 AM)Granfatherglock(07-14-2018, 07:12 PM)baldur Yeah you won't get good compression test numbers without a good battery.
It is a good battery, Exide 700CCA AGM.
(07-14-2018, 08:37 PM)supracrazy You would try to start and warm up the motor before doing a compression test. Or just try a wet compression test to see if cylinder 4 increases in compression. Could just be a ring not sealing correctly since it hasn't been ran in awhile... suck about the glow plugs
Thanks, I wish I could warm it up first. I thought about trying to get some water in it and plugging in the block heater, but I doubt the block heater will get it warm enough to make a difference. I'll get wet compression numbers as well.
[quote pid='88677' dateline='1531665304']
If it was cranking over slowly you either have a bad battery, a bad starter, bad wiring between them or a practically seized engine.
[/quote]
Battery and cables checked out good. You're right it could be the starter or a mechanical fault in the engine. That's what I'm trying to figure out with the compression test, haha.
I added a few drops of oil to 1-4. The engine turned over much better this morning, and #4 jumped up to about 220psi. Which, while still not excellent may show some promise for this this engine. I think it has sat for a very long time and the rings are stuck. I may regret it, but I think I'll hold on to this engine. At the very least it will be good for parts.
I do appreciate your help.