CL350 seized engine

[rubin]

While riding the other day – with an oil leak that was worse than I thought – the engine seized on my 350. I had left it sit for a week or so and did not think to check the oil before I started her up. After warming up I rode it with no problems, till about 10 min in. Engine seized. I checked the oil as the obvious issue, swearing at myself the whole time. It was low, so I went to a gas station, filled it up, and rocked her back and forth a little to free up the pistons. These freed up quite easily, and she started and I was on my way.

The issue I have now is that she backfires, and does not have as much power as she had before. A compression test I am sure will confirm scoring on the cylinder walls, but for now she runs ‘decently’. The question is, should I just look for a new engine or will a new head/piston/piston ring do the trick? Did I bend a valve and that is causing my backfiring? Can I figure this out without doing a teardown?

I really don't have much experience in this area so any help would be appreciated.

 

[dirtbag]

You probably roasted your rings. Don't jump to conclusions until you take the engine apart.

 

[bobjohnson]

Most likely, pistons froze in cylinders, rings stuck to walls. Walls will be scored, rings will be toast, pistons MIGHT be ok. Most likely backfiring is caused by compression being super low now (due to ridiculous gaps between piston and cylinder) and unburnt fuel being sent out to the exhaust pipes.

If you didnt snap the timing chain, its unlikely you bent a valve, because the pistons are still in time with the cam.

Pull it apart, see what it needs, price out the parts and then check to see how much a new engine is worth in your area. Also factor in the time, if youre looking at like 20 dollar difference, its worth the 20 bucks to get a known good running engine rather than tear yours apart. You can always rebuild yours on the side to make it even better than it was (overbore, hot cams, etc etc.)

 

[rubin]

Thanks for the ideas. I guess pulling her apart will be my next goal. Do you think she will make a 300-400 km trip before hand? It doesn't backfire unless in a certain RPM range under acceleration, so if I take my time I think I can avoid this. One pipe was a little weaker in the exhaust pressure from the feel of it on my hand, but I am not sure if this was the same before the incident. I need to get it from Hamilton, Ontario to Windsor since I am just in an apartment up here and I have my garage with most of my tools in Windsor. Going to try to ride it down I think.

Once I am able to tear it open I will be needing lots of tips, since I have never attempted this before. I am guessing I will need to pull the engine, lol, which is another thing I have never done. This should be a lot easier than trying to do the same on my XJ11. I will start a new thread on the process with pics, and hopefully people can chime in on all of my mistakes and errors.

 

[dirtbag]

Ride her til she dies.