Rusty valves

[joker]

Hi

I am just completed an engine swap for my 318is after timing chain damage. I have used low mileage M42 from E36 and swapped all necessary ancillaries, basically just kept head, block and timing gear.

Engine started no problem but will not idle properly, really hunts and runs rough up to 2000 rpm but ok after. Any ideas what are obvious things to check.

Also there is a horrible screeching noise coming from the engine, mainly when releasing throttle but noticable at all times. Sounds like metal on metal squealing. My suspicion is that noise is coming from the inlet valves. When I was part way through the change rainwater found its way into the inlet ports of the head. I dried this out and sprayed WD40 in there but I could see some surface rust on the top of the (steel?) valves. Does this sound like the problem? Any ideas for solution, its pretty deafening ?

Thanks

[Banjo1981]

I had a horrible screeching noise when I rebuilt my engine, turned out one of the bolts in the belt cover had worked loose and was rubbing on the rear of the crank pully!

[joker]

Cheers

Pretty sure not that tho. Seems to be coming from inside the head all the way along.

[Brianmoooore]

The nearest thing I've experienced to what you're describing was on a reasonably low mileage M40 engine, but one that unfortunately had been driven home after the sump had been holed.
Rough idle is usually an air leak. Have you blanked off the inlet manifold connection for the carbon cannister, assuming the E36 had one and the E30 doesn't?

[joker]

Hi Brianmoooore, thanks.

Presumably that was big end bearings or something then? No reason to think they are damaged. Mileage only 75k as far as I'm aware.

Used E30 manifolds etc so think all is ok. Will check for air leaks though, cheers.

[joker]

bump

[Brianmoooore]

I think the stub that I'm referring to is actually just on the throttle body. Is that the E36 or E30 item?

[joker]

E30. Everything bar the head and block are E30 items from original engine. Just head, block and timing gear from E36.