Owned for 15 years, purchased with 44k,now has 54k. Driven on a 1000 mi car tour last fall and stored for the winter in my CC car building. When I went to start it this spring it would not turn at all. Battery was weak so I replaced it with a new one. It took several tries before it broke loose and started and there was a significant knock at idle. I pulled both valve covers and didn't find anything out of order. At this point I let it set while I finished another project. Sunday when I tried to start it the motor was seized. Using a socket and breaker bar it would not budge. I was able to turn it in reverse direction for a few degrees but when I try to turn it in the correct rotation it stops 8 degrees from TDC and is SOLID. Anybody have a similar experience and should I pull the motor for investigation or is it time to cut bait and run. Thanks, Bob Smits, College Station, TX

The motor isn't "Siezed" , there is a mechanical bind at a certain point.

I'd say something fell into a cylinder or something got into the bell housing. I'd pull spark plugs, look in the holes for damage ( use a bore scope )

Disconnect the flex plate from the torque converter and give it a spin by hand. Don't use force as you might damage other good parts.

Pull the valve covers again and look for a valve being stuck open which would hit a piston due to a timing chain problem.Single row or double row chain?

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cad58y, no doubt you realize the engine should never be turned in the CCW direction. Difficult to determine what problems that may have caused. Using a bore scope you should be able to see if any valves are stuck open, causing a mechanical interference. It's possible there is a problem with the timing chain tensioner that is causing a mechanical binding. If there are no valves contacting a piston, you may want to remove the timing chain tensioner and verify the spring has not broken. The tensioner spring keeps the timing chain tight when the engine is not running. Once the engine starts oil pressure maintains tension on the timing chain.

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Fred Hoelzle

I'll counter the " don't turn the engine backwards " ,even though the manual says not to turn backwards, if the chain skips, it was badly worn to start with. The manual recommendation was likely so a worn chain would not come off while the car was in the shop leaving the shop to explain to customer that the previously running engine needs to come apart for a major repair.

Engines tend to stop against compression and can roll back a bit to varying degrees. The camshaft can also roll over a lobe causing it to snap forwards giving a similar effect to rotating the crankshaft backwards.

In the day, gasoline engines would get " run on " where the engine would continue to run ( poorly ) when the ignition was shut off, sometimes the engine would violently run backwards for a bit.

Thank you for the replies. FYI I am working with a retired Mercedes dealer mechanic He has checked the timing chain early on (single). We were able to run the engine with the valve covers off with no evidence of a valve problem. Also if you spun the engine with out spark the knock was not present. I am aware not to turn engine backwards but this was done as a last resort after the engine locked up knowing I was going to have to pull the engine and either tear it down or junk it. I will borrow a bore scope this week end. Also is there a good thread on removal?

cad58y, if you ran the engine with the valve covers removed and there is no sign of a valve problem why are you using a bore scope to inspect the cylinders?

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Fred Hoelzle

If you decide to remove the engine it is easier to pull the engine and transmission together.

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Feldman, I don't want to leave any stone unturned. I didn't personally view the valve train, my mechanic did. Mike, do you have to remove all the accessories and exhaust manifolds first. Where are the lift points? Thanks for your replies. I have played with Diesels since 76. This is my first gasoline endeavor.