3500 SCR Engine Repair

[CapPap]

I bought a 2001 3500 SCR with 680 hours on it last year. Ran good this summer until it started misfiring at end of season. Compression check shows zero compression on #1 cylinder (7.4L MPI Merc). Does the engine need to be pulled to sort this out ? ie. If it’s a head gasket or valve issue, can it be addressed without pulling the engine ?

[mmwjr]

First you need to determine why the compression is bad. A leak down test will isolate it to intake, exhaust valves or bottom end, rings or piston. Any signs of water or oil leaking outside the engine near this cylinder?

As long as it’s the top end the repair can be done without pulling the engine.

BTY: is this raw or closed cooling?

[CapPap]

Engine is close cooled. No sign of water or oil leaks around this area. Hopefully mechanic can isolate and resolve without having to pull engine. Thx Mike.

[CapPap]

Update: heads removed, reconditioned. Running great so far. Did not need to pull engine. ‘Tuliped valve’ was the problem.

[mmwjr]

Originally Posted by CapPap

Update: heads removed, reconditioned. Running great so far. Did not need to pull engine. ‘Tuliped valve’ was the problem.

I have seen this happen on exhaust valves. Water ingestion or running lean can be causes.

[CapPap]

Thanks. Hoping for a good summer season this year.