Engine 850: B5252S/2.4/10v: lack of power

[marc850]

Originally Posted by Nicks 850 broke!

Hi Marc In the last 3 years I've gone 2.3 T5 to 2.0 20v and then to 2.5 10v - the latter two are nominally same 140bhp output but 2.5 feels much more relaxed in its power delivery - I'd need to check the books but I think that not only the T5 but also the 2.5 have higher gearing than 2.0 - going from T5 to 2.0 I'd noticed I had to work the 2.0 harder (no s**t sherlock!) but that actually it was lower geared so revved higher at all speeds and not actually desperately good on mpg - the 2.5 is far more relaxed and I am seeing much better economy from it than the 2.0. I still miss my turbo though but have another about-to-be-17-year-old to put L plates on for this year and another one in 2014 so it's no turbos for the present. Nick

Hi Nick

Well you seem to have been through the range, quite fancy a T5, to be honest still do it's a car i've always wanted, you seem to prefer the 10v 2.5 obviously better on the pocket but must seem very sluggish compared to the T5 tho? as i mentioned i used to have a 2.0 V40 which was pretty resopnsive and i'm a bit dissapointed with my 850 s performance and if i can't increase the power or acceleration a T5 estate will be on the cards sooner than i think.

i shouldn't say this but i use my cars for work as load luggers mainly ladders and tools (i am a TV aerial engineer) i think i might be getting cursed now! but what better car is there for reliability, performance, space and praticallity, comfort, safety shall i go on? i love them! however i do look after what to me is a valuable investiment, plus it turns heads and gets my business noticed.

Marc

[marc850]

Hi

You mentioned an ect sensor whats this, and where would i find it?
also roughly how much of a difference did it make combined with the thermo on performance and mpg?

Cheers
Marc

sorry that was directed to stuv7010v, still learning with this forum business ha!

[marc850]

Originally Posted by stuv7010v

I second capt jack, I had exact same probs on my v70 10v, after changing the obvious turned my attention to thermostat and ect sensor. The car was juddering very badly from cold and had slight misfire under load when warm and felt "restricted" I replaced both thermostat and ect and have noticed a difference immediately, like a new car!

Hi

How much of a difference did you notice on power, acceleration and mpg? what is the ect sensor?

(sorry if i seem thick, but i need to know these things, and i'm no mechanic! but trying)

Cheers
Marc

[Paul 850 estate]

Originally Posted by marc850

Hi all!,

Sorry chaps but i've been working away and never had a chance to thank you properly for your very imformative comments, i've took every thing into consideration and it's nice to know that there are people out there whom really know there stuff!

One thing i didn't mention tho and i don't know if it will play a factor or not, but the service light is illuminated and was when i purchased the car. would this effect the cars performance? if so does anybody know how i can turn it off with out going down the obvious route of garages, some sort of sequence maybe?

Cheers.

You say the service light is iluminated, this should only stay lit for a few minutes after starting the car then go out, are you sure it's not the lambda light (orange with green upside down triangle) that's iluminated, that would cause it to be over fuelling..

[stuv7010v]

hi, the ect = engine coolant temperature sensor
its under the top hose connection to thermostat housing, easier to unbolt thermostat top housing (2 torx bolts) and lift out of the way. I think its 17mm spanner size to undo ect sensor, it has a short length of loom to a 2 pin connector.
advisable to replace thermostat and seal while you have it apart

[yevgeniy]

i saw that this was just mentioned, i'd second it, if its O2 sensor? That would put a brake on the accel, as was mentioned. Engine can't breathe out, so it will feel flat and sluggish. catalytic converter maybe jammed? i had mine plugged on a '99 Passat, it too was too unresponsive for my liking, i took it out, and just made a hole where all the honeycombs were supposed to be. car became much more lively.

heh here it a tip, those honeycombs use a bit of platinum, you can melt it out, sell it, that would cover a bit of money towards the new unit.

[Nicks 850 broke!]

Hi Marc - indeed you notice the difference after a T5 and when I have got all three sons through learning to drive (and preferably off to college and out of the house!) I'll see whether T5s are still out there in good order - I really lust after a banana yellow R though - brash fast labrador and bike carrier of the future perhaps?

Hope you're getting the problems sorted. Service light (if that is what it is) can be reset if its a phase I with under-bonnet diagnostic plug and lights not sure how you do it if its a phase II OBD-II plug in the coinholder. If it's lambda light then you've got some clues from others but really need to get a code out of it to tell you exactly what you're looking for - probably a mixture fault of some sort and that would explain low power. First place I'd go for that is looking for vacuum leaks which could affect air-fuel mix dramatically. Have you got Haynes manual - the codes are all in there for a flash code car.

Cheers

Nick

[marc850]

it's definately the service light, and it remains lit at all times, could this be causing restrictions do you think?

the car seems to be using quite a bit fuel aswel, not to sure what i should be getting mpg but i'm doing around 100 miles for 20-25 gallons (good, bad average?)

[marc850]

Originally Posted by yevgeniy

i saw that this was just mentioned, i'd second it, if its O2 sensor? That would put a brake on the accel, as was mentioned. Engine can't breathe out, so it will feel flat and sluggish. catalytic converter maybe jammed? i had mine plugged on a '99 Passat, it too was too unresponsive for my liking, i took it out, and just made a hole where all the honeycombs were supposed to be. car became much more lively.

heh here it a tip, those honeycombs use a bit of platinum, you can melt it out, sell it, that would cover a bit of money towards the new unit.

Ano' what your're saying i've done something similar to a car in the past, but surely drilling the cat would effect the emissions?

[yevgeniy]

Originally Posted by marc850

Ano' what your're saying i've done something similar to a car in the past, but surely drilling the cat would effect the emissions?

well, yeah, but i didn't have to pass emissions for another year on it, so didn't bother with it.
i didn't drill it. i used a big screw driver, and hammered most of it out