06-18-2013, 11:24 AM
Join Date: Jun 2013
1997 4 cyl. whistling when up to temp
I've read a ton of posts about issue but they all seem to be dead ends on the solution (unless I missed something). Hopefully someone out there can validate what I'm thinking???
Purchased this Jeep last week. Test drove and didn't have any problems. Got on the road home and noticed this whistling noise coming from the engine. Here are the symptoms.
- cold engine, any rpm: no noise, idle is ok
- engine @ operating temp: idle is high, whistle noise from engine
- removed air box to try and isolate the sound
- When spraying WD-40 and Carb Cleaning on the intake/exhaust manifold's gasket the engine bogs down then goes back to idle (rough)
- further visual inspection looks like the manifolds gasket, throttle body gasket have been changed recently
- additionally, wires going to some sensors to the TB look like they have been replaced, or re-taped
- finally, looks like the idler, and tension pulley's, rotor and wires have been replaced
I'm fairly confident that the problem is one of a few things: gasket is not seated correctly, manifold bolts not tight, crack in a manifold, crack in the head.
Please let me know what you all think and what direction I should go. I am very comfortable turning wrenches but need a suggestion for the best service manual I can get - the online Chilton manual isn't what I expected...