Is my M52 poorly?

Scania · 18 Nov 2010 at 15:02

Clearly, something is up.... 1996 e36 328i Auto 133k

On my return from Spain recently - having left the car parked up for 12days - I recall my engine being flat & hesitant when I was leaving the long term parking, I stomped on the throttle to join the flowing traffic & nearly got rear ended as the car pulled away as if I was giving it less than 1/4 throttle.....

After a minute or so, it seemed to clear up and was fine.

I used it over the weekend, but its been stood again as I came down with a mild dose of The Black Death

I have just gone to use it again & it seems worse.

It started fine, but did not respond immediately to the throttle, after a second or so it started to slowly build up revs, once @ 2000 rpm it seems to wake up and was happy.

I left it ticking over for 10 minutes, warming it up, and upon restarting, its seemingly fine again.

I am guessing its possibly something to to with the throttle setup? its not a cable iirc.

Any advice (including scrap it!) welcome.

matt_fsr · 18 Nov 2010 at 15:06

Have you checked your air filter for blockages/excessive dust clogging?

Matt82 · 18 Nov 2010 at 15:12

an engine control issue, be that sensor or vacuum hose related

im sure engine wise its absolutely fine

Scania · 18 Nov 2010 at 15:26

matt_fsr said:
Have you checked your air filter for blockages/excessive dust clogging?

Yes, air filter is fine.

Matt82 said:
an engine control issue, be that sensor or vacuum hose related

im sure engine wise its absolutely fine

Feels like a vacum hose is off or something like that, bit puzzled that its fine once warm, I'll have to try & find my Haynes manual to look at the hose layout.

tigerstyle · 18 Nov 2010 at 15:32

bad fuel?

Take it for a proper Italian tune up and report back, maybe it just missed you!

topbanana · 18 Nov 2010 at 15:37

Sounds to me like an ignition issue, coil or HT leads. They tend get get damp / crappy if a car is left

Scania · 18 Nov 2010 at 15:59

thepedster said:
bad fuel?

Take it for a proper Italian tune up and report back, maybe it just missed you!

Come to think about it, I have been running it on 97 / 99 octane pretty much since I had it, but did put £30 in at Asda (the regular cheap stuff) on my way to the airport......

I'll try la melodia italiana su, & report back.

I doubt it missed me.

aproctor · 18 Nov 2010 at 17:46

Could it be the O2 sensor or a bad spark? also some wild cars could be the throttle positioning sensor or even slack in the throttle cable?

Scania · 18 Nov 2010 at 17:58

aproctor said:
even slack in the throttle cable?

Its not got a cable afaik.

I have spent a while poking & pushing hoses etc, the HT leads seem dry...

It's been stood for a few hours again now, so I'll see if it does it from cold again when I go out later.

aproctor · 18 Nov 2010 at 18:01

R420LA6X2/4MNA said:
Its not got a cable afaik.

I have spent a while poking & pushing hoses etc, the HT leads seem dry...

It's been stood for a few hours again now, so I'll see if it does it from cold again when I go out later.

I did say it was a wild card.

In regards to spark, have you checked the plugs?

robnut · 18 Nov 2010 at 18:06

It has a cable.

I had a very similiar issue after the car stood for a while, no power, slow to build revs. Its proberly running on 4/5 too. Condensation had got into my coilpacks. Took them off, cleaned with wd40 and all was well.

mejinks · 18 Nov 2010 at 18:19

HG failure? Whats the water level like?

aproctor · 18 Nov 2010 at 19:21

mejinks said:
HG failure? Whats the water level like?

I would be surprised if HG failure is causing his problems.

Scania · 22 Nov 2010 at 12:35

Update:

The oil & water are fine, so I'm fairly sure the HG is ok.

Having left it for a few days again, this time I noticed it started & ran from cold just fine.

That said, I have now noticed a slight hesitation as I apply throttle when pulling away from a standstill. Its fine on the move in on / off throttle situations, but fairly consistently, hot or cold, it does seem to have an issue with the slightest hesitation on pulling away from standstill.

Matt82 · 22 Nov 2010 at 13:01

that engine will have some form of ecu-water temp sensor. do you know how you can tell if that, or its wiring, is duff?

may explain the hot cold variation

GeX · 22 Nov 2010 at 18:49

sounds like MAF to me.

just to quantify this;

Friend of mine has an Alfa 156 that does a very similar thing. When cold, it is totally flat. You can floor it, and nothing till around 2k RPM and then it'll suddenly pickup. It is still slow to respond to throttle changes mind. New MAF fixed it.

Alibaba99 · 22 Nov 2010 at 21:08

Matt82 said:
that engine will have some form of ecu-water temp sensor. do you know how you can tell if that, or its wiring, is duff?

may explain the hot cold variation

Haynes manual should state the expected resistance for both cold and hot running.

Scania · 29 Nov 2010 at 02:24

Update #2

A week (ish) on and the problem has gone away, I have reverted to the 97 / 99 octane diet and it seems happy again.

The hesitation issue also seems to have been banished.

No doubt thats now tempted fate & its imminent death is near!

godinman · 29 Nov 2010 at 08:16

Is it chipped do you know? Some of the aftermarket chips can make it run very badly on lower octane fuel.

Matt82 · 29 Nov 2010 at 08:21

both of mine are on aftermarket software, both with more timing etc and when ive had to get peasant fuel ive no had those symptoms.

id also check over your breather system to check thats all intact too.

at this sort of age id bet itd also appreciate a bit of water injection to steam clean the internals and lambda(s)