98 E36 320i turns off when warm

[Ghenghis 0]

I have a 1998 Sedan e36 320i done around 150km .

It has been a good reliable car till recently when i fixed an air leak that was making the car difficult to start when cold.

The car now starts easily in the morning but when it gets to temp it conks out and wont start until its cold .

I have replaced the coolant temp sensor (under the Inlet Manifold ) and then cam position sensor behind the vanos unit .

My next part i was going to replace was the crank position sensor  .

AA came out when the car first stopped and it had no fault codes and seemed to have both spark and fuel (checked fuel Pump and coils )

The radiator fan always runs even when the car is cold and the air con isn't running .

I have a couple of old sensors , cam and temp if anybody is having similar issues , happy to post for you to try .

I also have a scanner with adaptor from ob1 to ob2 MS309 Model which wont connect (has any one had joy using this model )

In the last three Months i have fitted new front and rear shocks , 17" Lenso wheels 215s and 235s  , New front control arms , sport style seats and a battery  .Has been a really good reliable car to now and would like to fix and keep .

Any ideas or suggestions would be greatly appreciated . My next part replacement will most like be the Crank position Sensor 12141703277 .

Cheers Gus 

 

Edited September 9, 2022 by Ghenghis

[jon dee 500]

4 hours ago, Ghenghis said:

The radiator fan always runs even when the car is cold and the air con isn't running.

I don't know what kind of control your car has for the fan, but if it has a simple thermoswitch, the switch has most likely failed. They are set up to fail in the "fan ON" state. If it has a thrmoswitch and the switch controls a fan relay, it is also possible that the relay may have failed. 

Cheers...

[Ghenghis 0]

24 minutes ago, jon dee said:

I don't know what kind of control your car has for the fan, but if it has a simple thermoswitch, the switch has most likely failed. They are set up to fail in the "fan ON" state. If it has a thrmoswitch and the switch controls a fan relay, it is also possible that the relay may have failed. 

Cheers...

Thanks for that , i wasn't sure if it was related to the other issues or not . When it was running well it would often take a long time to get up to temp and wouldn't quite get there sometimes . I will have a look at it thanks 

[jon dee 500]

4 hours ago, Ghenghis said:

It has been a good reliable car till recently when i fixed an air leak that was making the car difficult to start when cold. The car now starts easily in the morning but when it gets to temp it conks out and wont start until its cold .

I'm gonna assume that your car has an air flow meter and that the leak was downstream of the AFM. So the engine would have been getting un-metered air and running lean. Probably why it was hard to start. The DME would have been adding fuel, especially at idle and low rpm. It might take a little while to "un-learn" that correction. 

Does the engine conk out when you are driving at motorway speeds or only when you pull up at a stoplight ? 

Cheers...

[Ghenghis 0]

1 minute ago, jon dee said:

I'm gonna assume that your car has an air flow meter and that the leak was downstream of the AFM. So the engine would have been getting un-metered air and running lean. Probably why it was hard to start. The DME would have been adding fuel, especially at idle and low rpm. It might take a little while to "un-learn" that correction. 

Does the engine conk out when you are driving at motorway speeds or only when you pull up at a stoplight ? 

Cheers...

The leak was on the hose below air flow meter that connects to the rubber inlet hose .

The car starts and drives perfect until the temp comes up to a third then the car turns off and is hard to restart .

Sometimes it can be restarted and it runs for a bit then dies . Often it cant until hours later when it is cold .

It never does when coming up to a stop light or low revs .

It did used to conk out from time to time if at low revs or just stutter for a second if I was doing 25kmh or more .

This only happened once in a blue moon so wasn't such an issue back then  

[jon dee 500]

Engine will have a lot of enrichment at cold start and cold running, and since it runs fine for a while it is unlikely to be fuel problem. That makes some kind of electrical fault the most likely suspect. And as the issue seems to be heat related it could be a bad soldered joint in the DME or a power switching relay. First thing to do would be to check all the relays in the main junction box after the car has been running for a while. If any of them are HOT (like too hot to hold your hand on the relay) then replace that relay. Going inside the DME is not recommended unless you are just doing a visual inspection looking for obvious faults (which includes leaking capacitors).

Here is something I put together for another forum some years ago... information is still good

Electrical Fault Finding 03 - DRY JOINT in Soldered Connections
The problem of DRY JOINTS in soldered connections, particularly on PCB's, is
well known in the electronics and electrical industries. This fault is responsible
for a lot of the "Car starts and runs fine, but randomly shuts down, and won't
start until it has sat for 10 minute... " problems.

This pic is lifted from a good article on a Honda site, but what is written applies
equally to pretty much any older car that uses electro-mechanical relays. No need
to read the whole thing as the first paragraph describes the problem in detail.

http://www.tegger.com/hondafaq....html

So before you go spending your hard earned cash on new relays, take a look
inside and see if it has a dry joint. If it has, any electronics repair shop should be
able to fix it for a couple of bucks.

Cheers... 

[Ghenghis 0]

Thanks Jon , i will check the DME today .

When i have the battery recharged i will check the thermo switch and see how long it runs without conking out 

[Ghenghis 0]

Finally got round to fitting the new crank sensor .

Now It doesn't conk out when hot , instead just runs poorly all the time . 

Tried to have it scanned by a mechanic and they couldn't connect to the car .

Check all the relays and none seem to be heating up .

Might be time to sell for a Toyota or Honda .....

[KwS 2429]

5 hours ago, Ghenghis said:

Finally got round to fitting the new crank sensor .

Now It doesn't conk out when hot , instead just runs poorly all the time . 

Tried to have it scanned by a mechanic and they couldn't connect to the car .

Check all the relays and none seem to be heating up .

Might be time to sell for a Toyota or Honda .....

Being an E36 you will need a BMW specialist with an ADS connection to connect to the car and check for codes. A normal OBD2 reader wont work.

Old car life.

[jom 98]

98 E36 is OBD2.

What is energised after 30 minutes? Carbon trap? i know I had the same problem about 14 years ago but for the life of me I can't remember what fixed it. Old age....

[Ghenghis 0]

2 hours ago, KwS said:

Being an E36 you will need a BMW specialist with an ADS connection to connect to the car and check for codes. A normal OBD2 reader wont work.

Old car life.

I had a couple of adaptors but neither got his headset or mine to connect via the round to flat system  

[Ghenghis 0]

1 hour ago, jom said:

98 E36 is OBD2.

What is energised after 30 minutes? Carbon trap? i know I had the same problem about 14 years ago but for the life of me I can't remember what fixed it. Old age....

My one seems to be the old round OBD1 in the engine bay , neither of the adaptor would read from it . Would connect but not read .

[jom 98]

11 hours ago, Ghenghis said:

My one seems to be the old round OBD1 in the engine bay , neither of the adaptor would read from it . Would connect but not read .

OBD2 is round as well. The E36 went OBD2 sometime in 96.

[Ghenghis 0]

I have a basic scanner that has connected to every E46 , Toyota and Mitsubishi .

The mechanic had two different ones and neither connect