525e cutting out F@"K

Sun Mar 25, 2007 1:41 pm

Got an old D reg auto 525e that keeps cutting out at any speed. Have possibly traced it to the idle control valve (page 15 No.12 of Haynes manual)
The outer layer of the 3 wires (switch)was split there but I have put some amalgafying* tape round it for now.
Sometimes i can here it buzzing so presuming a fault/short there, other times nothing. I can take it off then replace and it usually (not always) fires straight up again

How much are replacements or can I get switches? Or if poss another way round it as I dont want what happened this morning to happen again (stuck on a dodgy hill!)

Sun Mar 25, 2007 3:25 pm

Reading up on other Bmw's you can clean these out? how do I go about that?

Sun Mar 25, 2007 3:53 pm

The idle control valve wouldn't really make it cut out under power. These things are a pain in the arse for this - if it dies, it's more likely a fuel thing - a total cut out is more ignition and could be either the DME relay or the TDC sensor on the bellhousing. The idle valves are cleaned out with carb cleaner. Have it disconnected from the rubber bellows but plugged into the engine loom, spray loads of carb cleaner in there whilst turning the ignition on and off. You should hear it clicking and clunking as it opens and shuts.

Get that engine out, in an E30, and the car weighed.

Sun Mar 25, 2007 5:51 pm

Whats a DME and TDC?

Mon Mar 26, 2007 9:14 am

Digital Motor Electronics, or 'Motronic'. It's the main system relay and it's the five pin relay on the side of the fusebox, the four pin one is for the fuel pump. TDC - top dead centre. Every engine management system needs to know where TDC is in order to provide a spark at the right time. The flywheel had a steel peg at TDC and a sensor that reads it. If that stops working, the ECU doesn't know when to spark, and consequently, it doesn't. These TDC sensors normally fail completely - that bastarding relay however can be intermittent and is probably the fault.

Mon Mar 26, 2007 9:28 am

So that'll be the issue with the 525e I'm collecting then mate!!

Tue Mar 27, 2007 5:47 pm

how much are those bastardising relays then?

Thu Mar 29, 2007 6:08 am

Well I took the DME relay off along with the fuel relay, gave them a clean. Only broke down once and that was on way home from work just as I got off a roundabout in Writtle. Luckily I got it started straight away to! No flapping about

Thu Mar 29, 2007 9:05 am

Andy is out of the country for a while mate, he'll not be able to answer you questions. Try Euro Car Parts, a Dealers or German Swedish French.

Alternatively run the risk with one from a scrappy!

Thu Mar 29, 2007 6:07 pm

Well...guess what it was after all this?

Battery terminal loose! It died on me today on way in to work just as I left yet another roundabout. I went to tkae the DME relay off to clean it and engine died again. Saw a spark from the battery termianl and it was loose! so I only had a 13mm spanner and a flat headed screw driver that I managed to bodge it up tight enough to get to work. have done it up now and all seems fine

Lucky I didnt start shelling out cash

Just got to fix the gearshift cable and exhaust now...plus loads of silly things that can wait a while...costly cosmetic other than fan blowing only cold air

Thu Mar 29, 2007 8:21 pm

cool, looks like mine has fallen through..

Thu Mar 29, 2007 9:16 pm

Wanna buy mine?

Fri Mar 30, 2007 9:35 am

Geeza, get yourself on to http://forum.bmw5.co.uk, there's a whole E28 community over there!!

Fri Mar 30, 2007 6:14 pm

That link dont work. Im on an E28 forum but its American!