Hi all ....finished the new head replacement Sunday and having charged the flat battery ... the engine started but a bit rough. Ran the engine for 15 mins to let the ecu think and before I changed the oil again. But the idle was so rough .... just keeping the engine running with a horrible knocking noise coming from deep in the engine. Bled coolant system and made sure heater worked ... all ok. Went for 5 min drive and stopping at lights etc ....engine stalls. on the road all seems fine, accelerates ok ( but I am keeping under 3000 rpm for now). Have taken the car to work the last couple of days (20 min drive) and idle is better but still not right. Seems to be coughing and the smell from the exhaust .... horrible heavy fumes. So she must be running rich ... any clues as to what I do ??
I have trawled the sight for idle related issues and most seem to be idle too high ... mine struggles at 600 rpm .... I think ... as the SI batteries need changing and the main battery being off line for 3 weeks hasn't done them any favours.
Temp gauge was at half way to begin with ... but coolant level kept slipping slightly yesterday... topped up yesterday evening and hasn't moved today (guess it was settling down a bit) and now gauge shows just under half mark. So no coolant loss thank god !!
I put in a new thermostat but didn't realise there was an up and down so tell me if I need to rectify this.
I guess there is no unwanted air getting in or it would run lean ... so I checked the resistance over the ecu's blue engine temp sensor but didn't know how hot the coolant was (engine was cold) and the resistance didn't seem too bad.I presume all the belts aren't too tight not that that should make a difference !!
The air filter is recent ... not more than 4/5 months old ...will clean the afm and icv with carb cleaner ... the icv still hums on ignition.
Thanks to you for giving me the confidence to do this work ... it was lovely when the engine sparked for the first time - and now so quiet ... lovely and especially to Brian and Adam !!!!
SO what's next as Bentley says mixture can't really be adjusted ... just disconnect battery again and see what happens ???
G
Head replaced and running ... but not right .....??
Moderator: martauto
-
chu346
- E30 Zone Addict
- Posts: 2403
- Joined: Mon Jan 10, 2005 11:00 pm
- Location: Leicester
Are you sure the cam timing is correct?
-
android
- E30 Zone Newbie
- Posts: 86
- Joined: Mon Jan 10, 2005 11:00 pm
What engine is it? Presumably an M20 325 if you've done the head.
My M20 took a few runs before the cooling system settled down, even after very careful and repeated bleeding, so I'd say that was normal.
If your idle was normal before taking it apart, it's not likely to be the AFM or say the fuel pressure regulator. It would be unlucky if an electronic bit failed just at the same time as you do your head. Of course, disturbing joints which have been in the same place for 15 years is always going to throw up surprises.
Timing belts are very difficult to mess up if all your timing marks were lined up on reassembly, as a new belt is so tight it will only just go on when it's exactly in the right position.
Check all the fuel pipes are tight and not leaking. Same with air hoses, especially the big fat one going to your throttle body. Check all the electrical cables are connected firmly and that there's no oil on the joints, especially on the crankshaft position sensor which 'looks' at your front pulley. This sensor could be causing the fault. That cable broke on mine just where it goes in front of the block, only being found by feel in its plastic sleeve. A repair is easy.
The oil smell could be the O rings on the breather pipe from the inlet manifold down to the sump. I had put my manifold back on, before spotting a new O ring at the bottom of the engine bay. Had to take it all apart again.
I think if you can't find the fault, you might have to gradually take it apart again, looking for funnies. At least it will be very quick and easy to do this time, as you know what to do now, and all the nuts will be well eased.
My M20 took a few runs before the cooling system settled down, even after very careful and repeated bleeding, so I'd say that was normal.
If your idle was normal before taking it apart, it's not likely to be the AFM or say the fuel pressure regulator. It would be unlucky if an electronic bit failed just at the same time as you do your head. Of course, disturbing joints which have been in the same place for 15 years is always going to throw up surprises.
Timing belts are very difficult to mess up if all your timing marks were lined up on reassembly, as a new belt is so tight it will only just go on when it's exactly in the right position.
Check all the fuel pipes are tight and not leaking. Same with air hoses, especially the big fat one going to your throttle body. Check all the electrical cables are connected firmly and that there's no oil on the joints, especially on the crankshaft position sensor which 'looks' at your front pulley. This sensor could be causing the fault. That cable broke on mine just where it goes in front of the block, only being found by feel in its plastic sleeve. A repair is easy.
The oil smell could be the O rings on the breather pipe from the inlet manifold down to the sump. I had put my manifold back on, before spotting a new O ring at the bottom of the engine bay. Had to take it all apart again.
I think if you can't find the fault, you might have to gradually take it apart again, looking for funnies. At least it will be very quick and easy to do this time, as you know what to do now, and all the nuts will be well eased.
-
GDBN
- E30 Zone Camper
- Posts: 1415
- Joined: Fri Apr 08, 2005 11:00 pm
- Location: Copenhagen
Hi.... put new o rings on the oil breather ...made sure the lower one was sitting in the block before I lowered the pipe in !! Will check fuel pipes but I tend to agree with you on the afm and icv ..... new bellows on the way .
Any other ideas, though ???
Any other ideas, though ???
-
Adammcf
- E30 Zone Squatter
- Posts: 1578
- Joined: Sun Jan 23, 2005 11:00 pm
Glad you got it running. Mine has only done 380 miles since I rebuilt it last week and mine is still idling roughish when cold but its getting better and better the more I drive it.
The same goes for the smell. It smelt really strong at first which got me worried but again the more I drive it the better its getting.
The same goes for the smell. It smelt really strong at first which got me worried but again the more I drive it the better its getting.
-
GDBN
- E30 Zone Camper
- Posts: 1415
- Joined: Fri Apr 08, 2005 11:00 pm
- Location: Copenhagen
Mine is slightly the other way round - seems to be better when cold and worse when warm ... still stalls ocasionally when I pull up at lights etc ... Have disconnected the battery as I don't think the rocker cover was airtight for the first ten minutes warm up after the head change ... though don't think it will make a difference ! So if it is better when cold I don't think it is the idle valve ... maybe I will just wait and see. But running rich long term is not good for the engine as it burns off the oil coating from the cylinders... anyone know how much a new blue temp sensor costs ?? Maybe I'll change that and see if it makes a difference ?????
-
android
- E30 Zone Newbie
- Posts: 86
- Joined: Mon Jan 10, 2005 11:00 pm
If its running rich and you are getting clattering noises, I guess it could be that you are only firing on 4-5 cylinders. You have probably checked that your leads are all on the right cylinders? Did you use new plugs?
it 'd be easy to take them out and check if any are blacked up.
What about leads. Mine were on so tight it might be easy to damage them when taking them off. I know PeteE30Tourer had to change his leads recently. They're expensive though, at Ԛ£75 a set, so you may need to get them tested. Try looking at them at night to see if any sparks run along them.
Do check the lead across the front of the engine. The crankshaft position sensor tells the ECU where your crankshaft is and when to fire the spark. If that gets messed up, there is no chance of getting your engine running right. Some engines also had a piece of cable from No 1 plug lead to a multiplug just by the inlet manifold, which does a similar job i think.
Another thing to check is the throttle position sensor. (It hangs under the throttle body) these can get full of thick, old oil (especially if you overfill the sump) and need cleaning. There's an article on how to do this on the Total BMW website.
it 'd be easy to take them out and check if any are blacked up.
What about leads. Mine were on so tight it might be easy to damage them when taking them off. I know PeteE30Tourer had to change his leads recently. They're expensive though, at Ԛ£75 a set, so you may need to get them tested. Try looking at them at night to see if any sparks run along them.
Do check the lead across the front of the engine. The crankshaft position sensor tells the ECU where your crankshaft is and when to fire the spark. If that gets messed up, there is no chance of getting your engine running right. Some engines also had a piece of cable from No 1 plug lead to a multiplug just by the inlet manifold, which does a similar job i think.
Another thing to check is the throttle position sensor. (It hangs under the throttle body) these can get full of thick, old oil (especially if you overfill the sump) and need cleaning. There's an article on how to do this on the Total BMW website.