Startup 'n' screech problem, but not as we know it.

[Touring_IOM]

Ok some days worse than others but the very first time I start the car it makes a screeching but not the belt slipping screeching, it's more metal on metal screeching. The revvs dump to around 400rpm for around 1-2 seconds then picks up and she idles steady at 1.5k. Drive a little with no problems turn the car off start her up and it's never to be heard again until a few hours when settled.

I cannot honestly figure out what it could be, I thought it might be the water Pump but that wouldn't drag the revvs down unless its SERIOUSLY binding also the fact that the temp stays sweet as a nut. Also thought it could be the alternator but that would dim the lights and only the rev counter would suffer not the actual engine speed. Stuck for idea's.

Edit: 1.8 m40 91K miles, timing belt changed 500 miles ago.

[hongkongfuey]

Oil pump?

[Touring_IOM]

Oil pump?

Wouldn't it make the cam knock like hell And/or destroy every living component in the engine, smell like hell and be on crap power? Also do e30's have a low oil pressure warning light? Just had a look at my oil too still sitting on full and clean as I put it in 500 miles ago.

[kman82]

Can you start the car from the diagnostics socket then you will hear roughly where the noise is coming from.

[Touring_IOM]

Can you start the car from the diagnostics socket then you will hear roughly where the noise is coming from.

Diagnostics socket Were's that? What I'll do is give me mate a call tomorrow fire her up and Ill have a look/listen. Also had a thought could the pulley bearings from the fan belt be doing it? As the engine block expands from heat it stops binding but as it contracts the bearings scrape? Don't understand unless it was dragging badly why it would drag the idle down too.

[kman82]

No idea about the idle mate but the advantage of starting it on the diagnostics socket is that if you leave the keys out of the ignition it will just turn the engine over rather than actually start it which might give you more of a chance to hear where the screach is coming from.

I've had similar problems and have learnt to live with them, my screach is coming from starter motor / fly wheel / clutch area. If i start the car with the clutch pressed down the screach is not as bad - Might be worth trying??

Location of diagnostics...

Near the top front left of the engine on M20s; on the bulkhead, just inside the fusebox on four pots. Big round socket with a cap screwed on it. (Smaller D shaped thing on early E30s).

[kman82]

Oh and its pins 11 & 14 you need to jump with a thick piece of wire

[Touring_IOM]

Ah now that'll help! I'll have to give that a go. I think the idle may be the inlet manifold as I think it has a hairline crack in it by where it bolts to the lower manifold. I'll give it a spray with carb cleaner without setting the engine on fire.

[Touring_IOM]

Tis' the starter motor that's making the noise. The car starts without a beat so I think it's being lazy and not disengaging from the flywheel at the right point. This wouldn't cause the car to dip on idle so all eyes are on that manifold. I'll put a wanted ad for one as I like new stuff. Thanks a million kman82.

[kman82]

Well this sounds similar to mine. I swapped the starter and still had the squeel though. Have you tried starting with the clutch pressed in? Does it make any difference?

[Touring_IOM]

Well this sounds similar to mine. I swapped the starter and still had the squeel though. Have you tried starting with the clutch pressed in? Does it make any difference?

I believe it does, IIRC.

[kman82]

Did you ever have any luck sorting this mate?

Mines going back into the garage for a nose around tomorrow.

[Touring_IOM]

Did you ever have any luck sorting this mate?

Mines going back into the garage for a nose around tomorrow.

Yeah, what it was, was the bearings in the starter motor had perished with dirt or something and were pretty loose. Bought a new motor and sorted it out.

Sorry for not replying