struggling to rev past 5000rpm?

[diduc]

Just changed motor oil (mobil1 5w50), oil filter (Cooper) & gearbox oil (redline lightweight shockproof) last week and now car is struggling to push past 5000rpm. Car was taken to trusty mechanic who serviced my car for past 3.5 years, no problems.

Have been using same motor oil for past 3 years so don't know what is the symptom.

cleaned filter, bit better but still car still very sluggish off and on boost.

Went up against catback exhaust r33 and struggled to keep up.

car has unichip retuned 05/04 stock boost 181rwkw. clutch is heavy duty daiken replaced 15000kms previously, daily driver, not thrashed. Cooper plugs done only 6000kms. redline oil and the oil filter is the only different thing I have used (previously castrol VMX80 and ryco).

[yogi000]

i had a similar problem on my r32.......nothing to do with oils. mine was my knock sensors. It was like i hit 5000rpm and it was sputtering and stuff......it was all revs no pull.

to check em all u gotta do is put ur ecu in diagnostic mode and it will spit out a code.

[aKTiVE]

When its 'struggling'

Is it running really rich and pouring black smoke out of the exhaust?

Does it backfire?

Does it clear up after 5000rpm?

I have had problems like this constantly over a range of cars with different things being the problem.

Once my car was really really sluggish down low and up top it was 'ok' but didnt go like it should. Turned out my ignition timing was retarded 12degrees or something like that.

Once it was my Fuel Regulator

Twice it was my Crank Angle Sensor (but when my crank angle sensors went it was way worse - car would shut off and not turn back on)

Spark plugs leads once caused my car to freak out a bit.

You have to do a bit of problem determination here =

oh yeah, and my mate had this problem as well, he did a reshell and somewhere along the lines when the place was fitting his engine, they put oil in the engine.... but it already had oil in it.

The car backfired, ran like absolute crap, very sluggish... absolutely offensive.

It had 8 litres of oil in it.

haha.

[diduc]

no black smoke or other symptom except car feels especially sluggish in third when it is should be pulling away.

revs built up slowly once 5000rpm is reached.

Thanks anyway, I put it down to the oil or the ignition timing (feels like pushing a potato through a straw).

[aKTiVE]

yeah my car did that when it was ignition timing... it sucked.

just wondering whether a collapsed muffler or blocked muffler would create the same issue... ? *shrugs*