172 rolling roaded / problems?

[oVerboost.]

And the result was okay I guess for a ph1 standard 172 with 100k miles.
155bhp with 156 ft.lb torque (1st run) then 164bhp with 155 ft.lb torque (2nd run).

I did ask them to also give their oppinion about the slight misfire at idle which they tested on the gas analyser and the hydrocarbons were really high. However what I am concerned about, is they tested the hydrocarbons after the car had been sat cold for half an hour. Am I right in thinking that they would be high if the car was cold? They told me next step would be a compression test which I find a bit odd as the car drives fine, pulls really well in all gears and has no loss of oil/water or mixing of the two. It also does not drink fuel and other then a cold start issue with what I am 99% sure is the idle control valve, is perfect (other then a lumpy idle that appears to be a very slight misfire but then again it might not). The exhaust at idle has what I can best describe as a very slight pop so when you put your hand near to the backbox you can feel it popping on your hand (but not a backfire or anything like that) and as soon as you accelerate even at low speeds it stops doing it.

I have, just for the sake of it put in some wynns oil treatment which it says will improve the oil, free any sticky lifters or valves and increase compression.

Any ideas? Would it really be a valve that has a problem?

Car suffers no acceleration problems, no smoke, no other problems other then a lumpy idle and the engine appearing to have the slightest of misfires at idle.

Thanks in advance for any advice/help.

 

[Gaz_]

They all have a slight lumpy/misfire at idle? Well my 3 MK2 RS's have?

 

[oVerboost.]

And does your exhaust sound "flat" at idle or does that to have a sort of pop sound to it? Thanks.

 

[Gaz_]

Every so often they give a 'phut/pop'. I'd say you have nowt to worry about if it drives fine. They lean out for emmissions on idle

 

[yellowbelly]

am i missing something here or is 164 bloody good?

 

[oVerboost.]

Is 164 good? Should they not be 170 standard I've not long had my clio and love it to bits already - its so much fun, but I got worried today and saw pound signs light up in front of me when he said hydrocarbons were so high - but like I said they did check them from relatively cold.

 

[sideways danny]

that's pretty reasonable power and very decent torque for completely bog standard. What type of dyno was it, and you you have a graph you can post up?

 

[oVerboost.]

I do have a graph, but sadly on of the first run as I forgot to pick up the print out of the second run, but it is very smooth with no dodgy flat spots or low points throughout the rev range. I will get it scanned in tomorrow and posted up.

The dyno run was carried out locally at Alan Jeffries Engineering Plymouth who have one of the best rolling roads in the country going by reports, check out their website for info www.enginetuner.co.uk not sure of the exact dyno though.

 

[oVerboost.]

Here is the graph from the first run... I have just noticed that the torque was actually about 140 ft.lb from what I can make out. Apologies, I thought it was higher but having opened my eyes this time, its less but still a good graph I would say....

 

[sideways danny]

not a bad graph. I wouldn't pay much attention to Alan Jeffereys advice though TBH.

 

[oVerboost.]

So do you guys also think the hydrocarbons advice was wrongly given? At cold would they be very high?

Obviously the 2nd graph was slightly higher bhp wise, torque was about the same.

 

[sideways danny]

by the fairly large difference in the 2 figures, the car was probably still warming up on the first run, so slightly rich

 

[0-100mphin15sec]

Seems low to me. Had mine dynoed at 170-176bhp on a few seperate occasions with just a cat back zorst and the removal of the accoustic valve.

 

[TimR26]

It's not low, yours could be a tad high. So many variables though so, whatever the reading, as long as the car feels good thats all that matters.

 

[tandino]

And also i personally wouldnt ever stick any oil additive into my car.
if youve got decent quality oil in there then sticking an additive in is a waste of time and money.
Oil co.s invest millions into their product, far more than a company like wynn's will invest on a new snake oil product.
The only way it will increase compression (if at all) is by being like tar in consistency when you pour it out and increasing the oils viscosity by thickening up the oil you have in the engine.
Personally id change the oil at the first opertunity, the cold temps we have at the moment you want free flowing oil in there not treacle.

Cheers Pete.

 

[Plummer]

Seems low to me. Had mine dynoed at 170-176bhp on a few seperate occasions with just a cat back zorst and the removal of the accoustic valve.

Sounds like an optimistic RR.

 

[nick.]

100k miles and lets say average from them 2 runs you have 160 bhp and the graph looks very good too. I would be over the moon with that as I have never heard of a standard 172 getting 172 bhp unless you go on optimistic ones.

 

[MarkCup]

164bhp for a standard 172 is par for the course. I've seen some run with much less than that!

 

[Riley!]

id be more then happy with that from a 100k 172

 

[stuart1989]

Yeah id be happy with that, well played

 

[0-100mphin15sec]

Sounds like an optimistic RR.

Both RR optimistic? Doubt it.

 

[Mike_182]

Both RR optimistic? Doubt it.

The one of the only 172s to make anything like book?

 

[Andyman]

Your BHP might be about average but your torque figure is well above average. Sure stock 172's are mid 130's to mid 140's area typically so looks healthy by those figures imo

 

[oVerboost.]

I will also add that one cylinder is also down on compression slightly so perhaps it will increase in bhp once its been fixed? (Exhaust vavle burnt out).

Car pulls really strongly in all gears, the exhaust valve must be a small problem with it as it only affects the car at idle and on emissions.

Cheers for the replies/comments.