BMW E30 Struggles To Exceed 85 Mph
Discussion
Gents, I am experiencing a rather odd problem with my trusty, long serving daily hack, an immaculate E30 Tourer. The car is an 1.8i, fitted with the M40 engine. The car has covered 155k trouble free miles, I acquired it with 36k on the clock. I have looked after the car meticulously, regular oil changes by myself and servicing at regular intervals etc.
The issue is this, if I accelerate in 4th gear upto 70 mph, the acceleration plateau's out- it simply will not accelerate past 70-75 mph. Even in 5th gear, the maximum speed I can reach is 85 mph. This issue is not due to a worn clutch slipping, I fitted a full clutch kit last month and the problem still persists.
I was considering having a compression test carried out. However, I don't think this is an engine related issue, it isn't burning oil & it appears to be running okay. The obvious possibility could be a transmission problem. Has anybody out there experienced this problem? Suggestions/advice please guys......
The issue is this, if I accelerate in 4th gear upto 70 mph, the acceleration plateau's out- it simply will not accelerate past 70-75 mph. Even in 5th gear, the maximum speed I can reach is 85 mph. This issue is not due to a worn clutch slipping, I fitted a full clutch kit last month and the problem still persists.
I was considering having a compression test carried out. However, I don't think this is an engine related issue, it isn't burning oil & it appears to be running okay. The obvious possibility could be a transmission problem. Has anybody out there experienced this problem? Suggestions/advice please guys......
You need one of these on the tailgate;
:P
On a serious note, both myself and a mate have 318i's (although E46). Crap accleration and power output on them both pointed to a clogged fuel filter. He changed his and it cured the problem, i never changed mine because i sold the car beforehand.
Hope this helps.
:P
On a serious note, both myself and a mate have 318i's (although E46). Crap accleration and power output on them both pointed to a clogged fuel filter. He changed his and it cured the problem, i never changed mine because i sold the car beforehand.
Hope this helps.
lance1a said:
Is there any lifter noise at any stage? I've had this on M40 motors where the lifter gums up and it feels like a rev-limiter kicks in at around 4000 rpm.
Yes, the lifters are a bit noisy. I replaced the hydraulic lifters nearly five years ago. The car bottoms out around 4,000 rpm & it does feel like a rev limiter kicking in........Question here for you - you say you service the car merticulusly however you have no idea when the fuel filter was changed last... Um at least once a year or same time as oil.
Can you rev the engine out in the first three gears - in fact you should be able tp better 85 in third anyway.
When did it start to behave like this was it overnight or gradual?
What is the in gear acceleration like?
Can you still accelerate as you would to overtake on an a road or b road
In neutral can you rev the engine out does it rev freely any noise?
Could be clogged injectors - what's the exhaust like when you floor it, like a diesel? If so injectors clogged.
Is it firing on all cylinders? Could be a ht or coil pack / dizzy cap or ht lead problem as in old worn out degraded.
Highly unlikely but it could be a badly corroded electrode on the sparkplug
what about the car battery is it holding full charge? Alternator problems.
The bad fuel is unlikely and to counter that try topping it up to dilute the issue
Could be air flow meter?? Had a similar problem with an old rover 216 se efi after stripping everything it turned out to be that.
Can you rev the engine out in the first three gears - in fact you should be able tp better 85 in third anyway.
When did it start to behave like this was it overnight or gradual?
What is the in gear acceleration like?
Can you still accelerate as you would to overtake on an a road or b road
In neutral can you rev the engine out does it rev freely any noise?
Could be clogged injectors - what's the exhaust like when you floor it, like a diesel? If so injectors clogged.
Is it firing on all cylinders? Could be a ht or coil pack / dizzy cap or ht lead problem as in old worn out degraded.
Highly unlikely but it could be a badly corroded electrode on the sparkplug
what about the car battery is it holding full charge? Alternator problems.
The bad fuel is unlikely and to counter that try topping it up to dilute the issue
Could be air flow meter?? Had a similar problem with an old rover 216 se efi after stripping everything it turned out to be that.
Welshbeef said:
Can you rev the engine out in the first three gears - in fact you should be able to better 85 in third anyway.
These won't even crack 80mph in third.To echo Welshbeef and others, is this a problem that has come on suddenly or over time? The easy and cheap stuff to do would be replace your fuel and air filters, it could easily be either of those. Failing that, these engines are known to suffer from cam wear; did you check/replace yours when you replaced the lifters? It seems quite likely to be the case from symptoms you have mentioned but change the filters first.
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