Engine 850: B5234T/2.3/20v/T5: my beast has a mind of its own

[marko_850_t5]

hey guys i have searched but to no joy


i have a 850 t5 wether the engine is cold or warm when i change gear, foot completely off the throtle it revs up half a thou then drops on every gear change?

also i wiped down the engine compartment the other day then today i changed the head light bulbs and noticed that there was a small amount of oil running down the outside of the dip stick tube thing and a bit on the manifold and the top rad hose any ideas what could be causing this ?

[dooby]

Hi,

I'm not too certain but I think a lot of people have said the manual cars hold on to revs a bit on a gear change. My car is a bit of a freak as it was an auto but is now a manual running an auto ECU so I don't have direct experience of this. Maybe others can comment if this is common on standard manual cars.

For the oil issue, could your Positive Crankcase Ventilation (PCV) system be blocked? This might cause excessive pressure in the sump, which could cause oil vapour to come out at the top of the dipstick. Maybe it makes it as far over as the radiator hose? Perhaps worth replacing the dipstick top O ring once you've established whether you need to change your PCV pipework.

Cheers, Pete

[John_C]

It's not uncommon on the manual 850 T5's, I had it and found adapting my driving style so I came off the throttle a bit earlier when changing gear helped. When I had my PCV system changed it got a bit better too, so as Dooby says probably worth checking that.

[needforswede]

My old T5 didn't rev up at all but it held onto revs when I was changing gear causing an annoying surge when I got into the next gear. Changing my vacuum hoses resolved this issue, altough I remain unsure of the reason.

[storming]

Could be the clutch needs bleeding, was with mine, GUNSON EASY BLEED is the only way i found. needs over 20 psi

[marko_850_t5]

thanks for the responses whats in volved with the clutch issues ?
can any one show me a pic of the hoses so i know where too start looking :P

[dooby]

Hi,

bleeding the clutch is not a bad job I don't think. No worse than bleeding the brakes, possibly easier (as there's only one bleed nipple). I used a Gunson bleed kit as suggested, and a bicycle tyre at 20psi. I reached down to the slave cylinder in the gap between the inlet manifold and the radiator pack. There's a rubber cover over the bleed nipple then you need a good 6 sided socket to loosen the nipple (it's small, 8mm maybe?) and then you can use a 5 sided brake spanner (if you can find one small enough) or an open spanner but I wouldn't break loose or fully tighten except using a 6 sided socket in case you round it off.

EDIT I've only done this once so maybe other members have addtional tips.

HTH, Pete

[glock19]

I had this for my manual R too. Only remedy is to use an auto ECU or mapping which removes this "spike" in the revs completely. If you are going for a ECU chipping, ask for auto transmission spec.

[marko_850_t5]

Originally Posted by glock19

I had this for my manual R too. Only remedy is to use an auto ECU or mapping which removes this "spike" in the revs completely. If you are going for a ECU chipping, ask for auto transmission spec.

did you check the crank preasure hose thing or did you just chip it ?
what does the auto chip have over the man chip to remove the "spike"/lift in rev's ?

[dooby]

Originally Posted by marko_850_t5

what does the auto chip have over the man chip to remove the "spike"/lift in rev's ?

I don't actually know - I assumed the map for the autos just had different values which meant this didn't happen. Be interested to hear, if anyone has any theories or a better explanation than my guess :-)

Cheers, Pete