E36 Down on power!

[JaamesE36]

Hi guys. I’ve got a BMW E36 Drift car with a 323 engine. I haven’t had the car long at all but it’s very down on power, almost like setting away in 2nd gear from standstill or trying to come out of a corner in the incorrect gear, even to the point it really needs a beating on the clutch to slide, even In the wet it struggles in 2nd gear and requires a lot of clutch kicks to keep going. the car is virtually dead until the Vanos system kicks in. The cars and idles etc perfectly fine, the car is much more lively when cold and certainly more flat and slow when warmed up and after drifting it’s very very flat and unresponsive. 

 

It seems to have no power until around 3.5/4K rpm. Arguements sake to initiate a drift you almost need to be st the Rev limiter before dropping the clutch. A little clutch kick won’t do anything, or if coming in on the hydro it again needs a big boot full of clutch to get the wheels spinning again. 

 

Ive read about work Vanos seals but people complain about poor idle and starting  however I have no issues with that. Is there a test for the Vanos seals or is it a case of just replace them and see if it’s any better? 

[Greydog]

Have you unplugged the Vanos solenoid to see if that makes a difference? If it doesn't then the Vanos adjustment isn't working for some reason (probably the vanos solenoid) 

First you need to establish which engine version you have 1st Generation 1992 on M50 engines had single Vanos operating on the Inlet cam, in 1996 (I think) the S50 engine was introduced with twin vanos. If the Vanos seals are shot then the noise will let you know

[JaamesE36]

I haven’t mate no, hence why coming on here for ideas like that haha. It’s single Vanos mate 

[JaamesE36]

When you say the noise will let me know. What noise exactly am I listening for? Hot or cold? 

[Greydog]

When the Vanos seals are gone it sounds like the top end is going to fall apart, loud rattle that's what I had with my 4.4 years ago the engine ran OK but it was so rattly I thought the chain guides had gone.

[JaamesE36]

strange as my car seems very quiet on idle. Like it should albeit a slight exhaust leak as the rubber book is missing from the gearatick and you stick it exhaust fumes after driving it. Which I will address this eeekend. But it does seem really quiet on idle 

[Greydog]

If all is quiet then that is an encouraging sign, doesn't mean the Vanos is working just that the seals seem OK.

Have you unplugged the Vanos solenoid? If the solenoid isnt working then at tick over all is normal when you open the throttle you are not getting any advance in cam timing so less power.

What else has been changed under the bonnet are you using the original DME what connections have been cut if any?

 

[JaamesE36]

To be honest mate I wouldn’t know. I’m going to unplug the Vanos solenoid a bit later. I bought the car with all the work already done. I’m not too sure what the DME is or what it looks like. I’m still very very new with bmw

[Greydog]

DME is the engine management, if your engine is quiet at start and tick over I am guessing the Vanos is OK but the solenoid is either sticking or broken. If you unplug and it makes no difference then I would say first take the solenoid off and clean it if that makes no difference change it.

[Bimmer Owners Club]

My Z3 Vanos seals have gone past their sell-by date....it is a 2.0 litre M52 engine with twin Vanos.

The symptoms are:

Poor idle and staliing
Lack of performance
Popping from the exhaust on overrun
Poor Economy

The seal kit to replace the originals are around £25 and I have the kit and intend to fit shortly (will post up a guide when I tackle the job)
The original seals weren't up to the heat and oil contamination hence the new ones are much improved.

Another factor to consider is that the Vanos relies on oil pressure to operate and if the oil quality is poor and the filter is partially blocked then the Vanos does not function as it should do.

 

[JaamesE36]

Thanks for that. I have no fault codes when scanned. The car starts and idles perfectly fine, there is overrun from the exhaust but it’s more crackle than anything but that’s probably because it’s a full straight through system with an e36 m3 backbox. The car is also slow. I had a Fiat punto making me look silly last night lol.

 

 

[Greydog]

What tool was used to read the codes? It needs to be a BMW capable system generic readers just wont do it, particularly as it seems to me your car has been cobbled together. The 323 engine should give around 150 to 160 bhp from memory. So assuming your engine is in tip top mechanical order (no serious wear) and the DME is actually correct for the engine? If those things are correct then it should feel lively in a stripped out shell.

However if the engine is worn and the fuel pump is delivering fuel for a 1.8 and the DME thinks the engine is something else it may run but you will never see any power.

If I was building the car (and I built short oval hotrods and rallycross cars in the 70's) I would 1st compression test the engine if it is down on compression nothing but a rebuild or engine swap will bring power. 2nd if the engine is strong then make sure the oil delivery system is as well as you will be going sideways a lot make sure its sump is baffled to ensure no oil starvation takes place. 3rd make sure the DME is correct for the engine or it may run but will never perform. 4th fuel pressure at the fuel rail is it correct, are the airflow meter and throttle body correct and working properly? 

Sorry if it sounds as though I am teaching granny to suck eggs but with out a solid foundation you are burning money.

[JaamesE36]

Snap On Solus machine was what it was plugged in with. I didn’t do any of the work on the car, I bought it exactly as it was. With the DME how would I know it’s the correct one for the car? Everything has been done to high standard, braided and solid lines from the master cylinder all replaced. Cage welded in. Custom CNC Cut arms. All polybushed etc seems no corners have been cut with the car so can’t jmagine something like fuel pump or DME being out of the 1.6 4 pot what the car original started life as  

[Greydog]

Sorry James but whoever you brought it from sold it for a reason? Which is probably the power issue you are suffering? Did he compete successfully?. The original 4 pot with a simple remap is capable of 130 to 150bhp the 323 should give 160 to 180bhp in a stripped out shell either should feel pretty punchy. So something is strangling the engine and not allowing it to give it's best, as I said in my previous post I think fuel pressure needs checking as does all the other stuff. Check www.realoem.com it's BMW online parts list I would look at the original 1.6 or 1.8 1 series engine parts if you have the Vin number put the last 7 digits in the search box it will bring up the original model. Get the part numbers for the DME and fuel pump and check against what you have in the car

The BMW DME will also take input from the Gearbox controller, ABS unit plus others. When I look at my X5 with my BMW 1.4.0 software I get 3 pages of control units that are scanned with 10 control units to a page each control unit can be interrogated. 

 

[JaamesE36]

Okay mate Thankyou, the guy was only selling due to funding his own business, all his toys were up for sale. Guy seemed genuine but then don’t they all? I will check everything out, Thankyou for the said link. Just very odd how it’s so down on power 

[Greydog]

That's what doesn't make sense as I said even in standard form and a stripped out shell it should go quite well. May be he ran out time/money with sorting the motor??

First step compression test then fuel pressure if they are OK. DME, MAF, and Throttle Body.

Dave

[JaamesE36]

Done a Compression test. All cylinders 175psi or above across the board. 

 

That rules that out. Tried to sort out the o2 sensor heater fault I have and looked for relay #3 which controls the o2 sensor heater, there isn’t one. It’s missing completely, the plug the wiring the lot. Can’t see anything for it. Would this cause the car to be down on power? 

[Greydog]

Compression is good by those numbers so 1 off the list.

O2 sensor signal or lack of will certainly not help as the DME can't set the fuel air ratio accurately. There should be 2 sensors 1 up stream of the Cat the other down stream they also need to be correct as their rating voltage/signal is different. I don't know about the E36 but often the cable length will be different to make sure they are in the correct place, unless of course someone has changed one for one of the "universal" ones ?? From memory the O2 sensor also retards ignition at tick over to maintain exhaust temp so a failed system could well be the cause.

Dave

 

[JaamesE36]

O2 sensors are both there and working. It’s the preheater that’s not working, I’ve been told the relay on some looms is actually in the DME box so will check there. Car idles perfectly fine. I have noticed the exhaust manifold closest to the fire wall has a small crack in it too. That’s not helping either. 

[Greydog]

The only things left are Fuel pressure, (pump filter and regulator) MAF and Throttle body if they are working correctly then I am running out of ideas?

[JaamesE36]

No codes for either, if fuel pressure was an issue wouldn’t I be having problems at the top of the Rev range too? Once’s it into Vanos it goes like a dream.