hello everyone. i am new on here. I have a 1992 318is manual trans with about 191k miles. About 2 months ago the car would not rev past 3k rpm when the car warmed up. it would do this is every gear and even at idle. I replaced the cpu, the mass airflow sensor, the cam sensor, the fuel prssure regulaor and smoked the intake with sea foam twice. I also put in a new o2 sensor. i also took off valve cover to see it the chain stretched and it was fine. None of this helped. i did a search on google and it appears that this car is notorious for this exact problem. no one really puts what fixed it though. some said it was the cat, or mass air flow. i cant disconnect the cat to see if it revs when not on car casue the bolts are to rusty. Anybody have any clue what this could be,. thank you in advance guys.
The E12 5 series was introduced in 1972. It was available as 4 door sedan.
There were two models available: the 520 and 520i. Both models had a M10 four
cylinder engine. The 520 had 115 HP and the 520i 130 HP. In 1973 the 525 came
available. It had a six cylinder engine with 145 HP. A year later the 518 was
introduced. This model had a four cylinder with just 90 HP.
Ive replaced the camshaft position sensor on my 98 e36 problem was still i then realised it had a lack of back preasure fault was the cat blocking the exhaust sort my running issues out runs perfect now
Hey Im having the same exact issue as you! My car is a 92' 318i. Form my research it looks like it could be any number of issues. I've just replaced my cat and i'm still having the same issue. Revs and drives fine when cold after sitting over night. As soon as it warms up, like 10mins into driving, the motor wont rev above 3000 or some times even 2000. When I'm pushing the end of where its being "limited" i get some backfiring. There is no CEL that shows up but because its OBD1 i'm not expecting it to.
My question now is, could it be the cam shaft sensor? I've unplugged it while idling and there is no change in the engine at all. I would expect the engine to die when i unplug the cam shaft sensor but nothing happens. Is that correct?
Thanks for the help. Ill let everyone know what i find out.
had the cat broke up or just blocked up if it broke up it could be possible that bits of the internal part of the cat have blocked the exhaust further back failing that i would start with a cam sensor if its possible get a code read on the car see what faults come up but on my car i had the cam sensor unpluged and it still ran but whats strange is that its fine wen its cold but faulty when it warms makes me think the fault is more mechanical than electrical but it is very possible that the cam sensor is sending an incorect signal witch could cause this type of fault so thats where id be starting whith the cam sensor as u have already replaced the cat hope this helped u out
There are a couple posts in this forum that have people experiencing the same issue as you. I read through a few of them and it seems like you replaced or did what most of them did. The seafoam, cam sensor, etc.
What's left to consider is the cat and have you looked into your knock sensor? If that is malfunctioning it will cause your car to go into limp mode. The cat could also be broken which means rusty bolts or not, you might want to do what you can to get that off and see.
Ya I have replace the crank shaft sensor. N spark plugs n still ther.
When I unplug my battery than hook it up it will run fine for 15 mins than bak to the rpm nt goin pass 3500.
My next change is the ecu but idk if that will fix it. Did changing your ecu fix your problem?
I didn't have this problem on my car but a friend of mine runs a shop and a customer brought their car in with the same complaint. They ended up replacing the ECU after all else failed...seemed to do the trick and the car ran normal.
Look into it. Might just be your problem too Hopefully it helps!!
Ok n also yu said a failin. Knock sensor causes the bmw to go to limp mode.
The shop that checked my car says my knock sensor #2 is failin can that solve the problem? Or should I jus buy a new ecu??? Thanks again
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.