m20 325 issues

Thu Jul 21, 2011 10:21 am

I've been noticing a few problems with my engine, first of all a few people have told me that when following me and i give it a bit of right foot there is a burning/oily smell which i also notice when coming to a stop ie. off the motorway.

When driving around slow and then accellarating hard i notice all the power isn't there but after letting off and accellarating again its back to normal.
And lastly, intermitantly the engine feels rough (like there is some resistance) at 2k rpm whether driving or sitting still.

Can any body help?
Cheers.

Thu Jul 21, 2011 10:40 am

Has it been thoroughly serviced recently ?

valve clearances set ?

What condition are the distributor cap, rotor arm and plugs in ?

Throttle body cleaned out and TPS cleaned and set ?

Burning oil could be valve stem seals or something more serious

Thu Jul 21, 2011 10:41 am

Smoke would be Valve Stem Seals or Piston Rings usually. Cross finger for the valve stem seals as its a much cheaper and quicker job.

Thu Jul 21, 2011 11:09 am

New plugs and set clearances 1 week ago, rotor and dizzy unknown, throttle body cleaned and tps not cleaned but set. The car has been looked after previously so assumed most of the stuff was OK.
One thing to note there was oil on the plugs i removed, not on the tip though further up?

Not noticed much smoke out the exhaust.
Just to note when i say rough running the engine isnt lumpy or anything like that its quite hard to explain but like vibrating/rough and you can hear it as well.

Thu Jul 21, 2011 1:12 pm

What condition is the engine earth strap in? the smell of oil could be a leaking valve cover with oil being burnt on the exhaust manafold.

Fri Jul 29, 2011 7:41 am

Rocker covet gasket might need to be replaced it was on and off a few times. I did the clearances and another occasion took injectors out to be cleaned so gasket could be past its best.
When the bbtb was fitted the engine was always a bit rougher and I assumed it was just the air flow through the bbtb as it was much smoother on original tb.
That engine had a sniff test and is ok. Compression test showed one cylinder is down on the others but not by anything significant. Could be early sign of valve seal ware. Thats what I thought but oil levels don't drop and its not smokey. I made sure it got fresh oil every 5 or 6 months. If it had a trip to KH it got fresh oil before and after.
I don't remember and hesitation on revs, but that could be down to tb or an air leak I'd guess.

Fri Jul 29, 2011 12:47 pm

I have the same problem as the original post, also have a touch of oil the spark plug nearest the bulkhead but futher up nearer the thread of the plug.

I think the rocker cover gakset is at fault, if it is leaking oil could it also allow air in??

I'm replacing mine this weekend so i'll let you know if it helps.

Fri Jul 29, 2011 1:26 pm

Oh I forgot to mention I put a small dab of copper grease on the plug threads for ease of removal at the time of plug change - are you sure it is not that you found on the plugs?

Fri Jul 29, 2011 1:34 pm

mb15 wrote:I have the same problem as the original post, also have a touch of oil the spark plug nearest the bulkhead but futher up nearer the thread of the plug.

I think the rocker cover gakset is at fault, if it is leaking oil could it also allow air in??

I'm replacing mine this weekend so i'll let you know if it helps.

Check carefully the run of the thottle cable,it's not unknown for them to get trapped between rocker cover and head....