3k+ Rev problem on E36, M44 Engine - BMW Forum

StumpsterDHR · 10-15-2008, 11:44 AM

Hi to all.

Firstly I've run a couple of searches on here and not found anything that I feel can help me.

I bought my first BMW, an E36 Compact 1.8ti, (M44 Engine) a few weeks ago and all went well for the first week.

The problem I have is that the car suffers from a lack of power when you apply the throttle more than 3/4 and won't rev past 3000rpm. It doesn't matter what gear your in and is still a problem in Neutral.

It's not consistantly 3000 rpm. When colder the car will go to around 4k, but after 5-10mins it won't go past 3k. Holding the throttle open at 3k actually causes the car to drop revs down to around 2500. It feels like the car is being limited, it wants to rev higher but just seems to bounce back. If your gentle (1/2 throttle or less) you can coax it up to about 3500 rpm.

I have changed the Mass Air Flow Meter and this morning changed the fuel filter. The car is currently running on the driveway at 2k rpm with some Redex Petrol cleaner in the tank, i'm hoping this will help.

My question is, what should I do next?

Things that may be useful:
BMW 318ti, Compact, M44 Engine.
88,000 miles on the clock.
The car has a full BMW service history. Nothing major has been replaced. Serviced every 10k miles or so.
Everything on the car is standard.

There is a knocking coming from the Exhaust. It sounds like it's coming from the box in the middle. Is this the Cat? It does it under idle when cold, but only above 2000rpm when warm.

I have a feeling the car may have been sat for around 6months prior to purchase. The previous owner signed the logbook to the dealer in april and I bought the car at the start of this month.

The car ran fine for about 150miles before any problems. Admitedly I drove it like a pansy as I didn't feel comfortable in it at first. I did bounce it off the redline pulling onto the motorway after about 10mins of driving though.

Before the problem I did a couple of 30 mile or so trips, nothing Intensive and nothing that pushed the car hard.

The problem has gradually gotten worse. I managed an 80mile trip last week by keeping the car below 3000rpm and keeping off hard throttle. It is now next to undriveable though.
Yesterday it stalled just doing a short loop around the block and the Idle became erratic upon restart.

The idle has now settled at around 750rpm though and doesn't really fluctuate much.

I think thats everything.

So, what do I change next? Or is it off to the BMW Garage? The problem with taking it to a garage is that I don't trust driving it more than a couple of miles.

I don't know much about BMW's, or cars in general but i'm happy having a crack at anything. I used to Service my old Vauxhall without any problems and the BMW doesn't seem much more complex.

Thanks in advance guys and girls.

Dave

marti5 · 10-15-2008, 01:35 PM

It sounds to me very very much like PCV valve failure.

StumpsterDHR · 10-15-2008, 02:08 PM

Redex hasn't worked. The Engine ran for around 2 hours on 2000 rpm and theres no improvement.

Additionally I forgot to add that there's no apparent misfire. I've checked the plugs and leads and both seem in good condition.

Additionally I just changed the two small black boxes on the front of the engine as you look at it. Both have little wires on clips going into them. I think ones something to do with the Idle and the other with the throttle sensor? I don't really know.

I have a previously working donor car with M44 engine that i can take anything off I require, hence the two new parts this evening. It's a friends car that he wrote off driving into a small broken brick wall at the weekend. Bad luck for him, but useful to me!

PCV Valve you say? I shall go find out what that means just now and set about getting it put right.

Dave

marti5 · 10-15-2008, 02:20 PM

Its no good getting one from the donor car, you will need one from BMW.

StumpsterDHR · 10-15-2008, 02:23 PM

Oh, ok.

I was struggling to find anything on the internet about one anyway.

I'll get one ordered up tomorrow then.

Thanks chap.

Dave

StumpsterDHR · 10-17-2008, 02:39 PM

Update

Fitted a new PCV Valve this afternoon. Whilst doing this I also disconnected the battery for 45mins for the ECU to reset?

I then ran the car on the drive at 2200 rpm for 15mins before going for a drive.

The problem is still there. I spent 5mins driving around playing with the throttle to no avail.

The only new symptom is that it bounces in 2nd gear, like when your a learner and you lift off the clutch to fast. Revs are around 2000 when this happens.

So, next?

Dave

marti5 · 10-18-2008, 02:27 AM

You say you have changed the MAF is it genuine BMW?

StumpsterDHR · 10-18-2008, 12:18 PM

The MAF came off a previously fine BMW 318ti M44 Coupe. The Donor car was running fine until he wrote it off hitting an already broken wall in a car-park. The Donor car was still running fine when the MAF was pulled off.

Dave

marti5 · 10-19-2008, 03:10 AM

Could be camshaft sensor, your best bet is to run diagnostics

agtur2001 · 10-22-2008, 09:49 PM

Hello,

I'd go to a garage where they can run a diag for about $100.00 bucks. Hopefully it's something easy to fix.

Sounds like you already replaced the two items that went out on my E36... MAF and Oxygen Sensor... Plus I always use Super Unleaded and occasionally Chevron Fuel Injector Cleaner to clear performance issues.

Good Luck

TurboB3 · 10-23-2008, 04:32 PM

Have you done anything to your motor lately, or work on anything around it? This exact same thing happened to me at 3k rpms and I couldnt figure out what it was until i remembered working under the hood. I backtracked what I did and found that I had left a sensor not completely screwed in. I cant remember if it was on the motor or the trans, but I remember it was around that starter.

StumpsterDHR · 10-30-2008, 08:25 AM

It turns out it was the Catalytic Convertor.

One of the baffles had broken away and was jamming against the one behind it, blocking the escape of exhaust gases.

£160 fitted and all is good again.

Thanks for you help and suggestions guys.

Wheels, custom exhaust and some custom doorcards and speakers are now on the list.

Dave

marti5 · 10-30-2008, 10:22 AM

Thats great news youve sorted it out, BMW's hey strange beasts.

StumpsterDHR · 03-05-2009, 03:09 PM

To update:
Obviously the CAT fixed the problem but I felt the need to replace the stock exhaust for something better quality.
I didn't want some 'Boy Racer' style cannon hanging from the back and I didn't want to piss my neighbours off either.

I ended up going to Bells Silencer in Swindon, they fitted a stainless, larger bore exhaust and tidy looking tailpipe for £260.

Overall I'm impressed, it's louder than the stock one without being silly, it just seems to suit the car a little better. It's loud when I fully depress the throttle and then between 3-4.5k revs. Either side of that band it quietens down again.

I'd fully recomend them to anyone looking for a tidy exhaust.