: Cams replaced 2000 DTS



Mr Evil
04-26-04, 01:13 AM
I had the cams replaced at 50,000 miles due to rough idling, car seem to run great after major surgery......however after car has been sitting for over 5 days upon starting the car I get extremely rough start, sounds like a diesel engine starting up and sounds that way few a few seconds! Is this someting I should be concerned with? Should I take it back to the repair shop? Any idea what is causing this?

ShadowLvr400
04-26-04, 10:20 AM
Sounds like oil drained out of the heads, but 5 days isn't enough time for that to happen... Although if the oil pump is going bad, I dunno... Bbob will probably have a better idea.

BeelzeBob
04-26-04, 01:47 PM
I had the cams replaced at 50,000 miles due to rough idling, car seem to run great after major surgery......however after car has been sitting for over 5 days upon starting the car I get extremely rough start, sounds like a diesel engine starting up and sounds that way few a few seconds! Is this someting I should be concerned with? Should I take it back to the repair shop? Any idea what is causing this?

Did it only do it the one time after sitting for 5 days??? If so, I wouldn't worry. It sounds like a stationary lash adjuster may have bled down during the 5 day soak. Could happen if the cam happened to be at max lift when the engine was shut down....not usual but could happen. It if keeps it up I would definitely go back to the shop to mention the problem...

Are you hearing a "knocking" noise like the cold carbon rap that has been discussed?? If so, a few WOT accels should clear the carbon out of the combustion chamber...that's all it takes.

95Concours
04-27-04, 03:27 AM
Replacing the cams at 50k miles is common?

BeelzeBob
04-27-04, 04:48 PM
Replacing the cams at 50k miles is common?


Uh....no....not at all....

There was a running change on the cam profiles for the 2001 model year . The cam lobe profiles were changed slightly to allow a smoother idle....slightly less overlap in the valve events. Engines built after late fall of 2000 received the revised cam profile. There is a supply of the revised cams in service for owners that have a 2000 or early 2001 engine that they feel has an objectionable idle. The update involves a complete cam change (all 4 cams) and a reflash of the PCM. The revised cam profile does result in a loss of 2-3 HP....not enough that the advertised or rated power was changed..but there is a tiny loss.

I think this is what was being talked about...not a degraded idle due to a failed cam or defective part.

The cams in the engine would typically run for several hundred thousand miles.....in either the 93-99 or 2000 and later engines the cam and lifter interface is very robust and is not something that typically ever has a problem.....