Lumpy idle??

[hammoj28]

My 318is has a lumpy idle for some reason. When its cold its smoother but when it warms up its more lumpy. I have changed and cleaned the idle control valve but that made no difference really. I have checke some hoses and taped some up. Didn't make much difference. A guy at a bmw place listended to it and sed my cam sounded a bitty funny but he didn't say exactly what. Any clues. A lot of people sed the 318Is tends to have a lumpy idle. It doesn't seem to effect the drivability of the car though. Also i think my manifold might be blowing ever so slightly but im not ebven sure this would make a difference.

Heres a piccy.

[Bob_S]

the manifold makes one hell of a difference to idle if it is blowing, my is has a steady idle but it isnt smooth not by a long way.

[hammoj28]

Im not sure if it is blowing. I think it must be as the exhaust has been checked but theres still a slight blowy noise. How do i check??

Yeah it idles smooth and does not hunt but is just lumpy if you know what i mean?? Maybe this is normal??

[Bob_S]

mines shakes on idle and it's a good solid engine so dont know your timing may have been advanced at some point in the cars history?

[kirils]

i've seen cars that their engine is spending oil and in bad condition and have not that rough idle, on my 320i i had really good idle untill i had the timing belt changed so it can be the timing, like in my case, also it can be bad sparkplugs bad wires for the sparkplugs, etc...

[jagtech2002]

by lumpy idle,do you mean it sounds like it misses ocassionally?

[Dan318-is]

by lumpy idle,do you mean it sounds like it misses ocassionally?

This is what i had, and it was a missfire, turns out i was running extremely lean on idle. adjusted the air flow metre and that was that.

your head looks clean mate, so im not sure what he means about the cams, are there any scores on them?

when you say lumpy, do you mean it hunts? or is it higher/lower than it should be (should be about 840ish rpm)

what did you clean the IVC with?

[eko]

Any of the breathers split/damaged?

[Bob_S]

if you can get a sound clip from around the engine bay it might help shed some light on the matter mate? any chance of that?

[hammoj28]

Hey all. Didn't think anyone had replied to this post. sorry. Was a bit late.lol. Will try get a sound clip asap. It doesn't really hunt just shakes like bob ses, kinda lumpy like its a v8 or summat.lol. Not that extreme. Hard to explain.

Used carb cleaner for the idle control valve.

Tempted in adjusting the airflow metre. How hard is it to do and what way do i turn it.lol.

Yeah, i though that the head looked fine. The cams look perfect to me but im no expert. No scratches or lumps or anything.

The car seems to drive fine just idles weird. But iv never driven another IS so i dont know wether it drives fine.

There was a pipe that goes into the bottom of the icv was split but i taped it up and its pretty much sealed. Might have to get a new pipe but i dont think its that. Will Have to incpect them all i suppose.

[kevin316i]

How does the car behave at low revs when driving, such as in slow moving traffic? Any problems? My iS had a lumpy idle and used to drive poorly at low revs(jumping). Found the CO levels were out of whack and problem was traced to a vacuum leak on the intake manifold, problem with one of the gaskets.

[hammoj28]

Yeah, its pretty crap to drive in traffic. Jumps and jolts, doesn't wanna drive smooth at slow speeds. Hmm, could be that.

[Bob_S]

you have a vacuum leak then mate, my 316i used to be like that until I blocked off the tube that is used on cat cars.

if you whip off the intake manifold (doesnt take long) you will see a forray of tubes one of these or all of them are more than likely split and thus will be causing the problem they are not too expensive from BMW themselves so that would be my first port of call with the usual line of, is there any discount on these?

If you want to know how to get the manifold back on easily I will PM you my phone no. I'm off all week so dont struggle or hesitate to call

[hammoj28]

I hope it is that as it sounds cheaper than cams.lol. I might be able to do it in the week sometime but im not sure. Will pm you and let you know when i do. Thanks very much for the offer mate. Will prob need help.lol.

[Bob_S]

it's not rocket science tbh but it helps to have another knowledge source

[Bob_S]

Shaft! just thought it doesnt rasp like a fukker about 3/4k does it? if it does it's possible your chain has become more slack than an amsterdam whore and well... could mean serious problems

I had my chain done by a specialist who charged £230 all in

[320Touring]

Still trying to sort this dude?hmm

Personally, I didnt think it was too bad

Bob_S-as for the chain, we changed the tensioner for an e36 one, and it made some difference, so last i knew, the chain was tight

[Bob_S]

well that rules that one out...

I've found IS's arent exactly perfect on tick-over mine. I asked for my timing to be ever so slightly advanced when I had the chain replaced and it's a touch lumpier than my mates or rather his used to be smoother but he's fudged it now bloody fool

[E30BeemerLad]

my money is on the inlet manifold gasket

does it jerk like a good'un when crawling in traffic on very light throttle opening/ maintaining a constant say 30mph in 3rd for example?

[hammoj28]

I hope its not the chain. It does seem to make a chain rattle when its high revs!

Yup it jumps about at slow speeds in traffic. Hope its something like that. could get a new gaset i spose.

[GBE30]

Hello mate I have the same problem with mi IS.

There are quite a few hoses connected that use the hot water to heat the vair in the breather system I guess the is for cold starts etc.

http://www.realoem.com/bmw/partgrp.do?m ... d=19900100

Look at the engine cooling system and fuel preparation system and inlet manifold on the attached link. Gives you an idea of the level of task in hand. To me it looks simple but as always with old bolts use good non worn tools and dont over tighten! May be worth just nipping up the inlet manifold nuts one may have vibrated loose.

Looks like the top part of the inlet manifold needs to come off to aceess all hoses etc. I intend to go down get the hoses I need and gaskets etc and give it ago.

All my hoses are persihed beyond repair so I need to change them.

Listen to the timing chain using a screw driver should help identify any rattles etc and maybe stop worry taking over.

I maybe off for a trip to BMW tomorrow lunchtime will let you know numbers and cost for boots hoses gaskets etc.

Cheers

Gareth

[GBE30]

Hoses that I have ordered and prices.

11611717761 - Top section inlet manifold gasket £5.88
13541743261 - Throttle body gasket £0.73 x 2
13711721431 - Rubber boot between air filter housing and throttle body £16.51 (Non in UK or Germany apparently)
13411721971 - Hose top of ICV - £2.39
13411721972 - Hose bottom of ICV - £4.34
13411721907 - Vent Hose - £4.05
13411721909 - Hoses vent hose - throttle boot - £2.39
11151717858 - Hose from vent hose to rocker cover £4.77
11151739266 - Vent Hose (2 Types check yours) - £4.94

All in inc VAT £54.90 so they say i havent added them up!

Think maybe i should do the manifold to head inlet gasket too just incase!!!!

Try also checking for leaks witha can of carb cleaner!

Hope this is of some help.

Gareth