Mk2 172 Engine Problems

[Gareth]

Guys,

I need some advice, I am at the moment experiencing quite a lot of problems with the enigne in my 172, it is kind of related to the cold start symptons that these cars have, i.e drive it for 0.5 mile and its fine. But, nowadays everytime I go to start the car from cold and I put my foot on the gas it doesnt want to know, the car shakes like mad (like it is misfiring) until it has warmed up, but it does it in the morning going to work (when its cold), and now even when going out of work (when it shouldnt really be that cold), the car is booked in renault on saturday anyway, but I was wondering whether I should ask them to take a look at the engine software (again), I wasnt sure whether it was because the engine is nackered, (because to be honest, sometimes i drive it like i stole it), but thinking about it seriously, this only occurs when the engine is cold, once it has warmed up it is absoultely fine, and drives like a dream. If the engine was misfiring then it would do it all the time?, but it doesnt, only when cold it jumps, so this makes me think its the cold start symptons? Any views/ideas? (technically minded people)??

Thanks,

Gareth.

 

[Gareth]

anyone??

 

[Chad]

Who many miles have you done??

 

[Gareth]

25k, serviced at 12k and 24k by Renault

 

[Pete]

Mines in for a service today and Ive asked them to look at it for me. If I remember later Ill post up if theyve fixed it!

 

[Chad]

If you drive it hard I reckon the spark plugs could be a bit worn....there supposed to last for 60,000 IIRC, but I reckon if you drive it hard they could well need replacing by now.

 

[Gareth]

but it only does it when the engine is cold? when the temp gauge reaches the "norm" the car is absoultely fine, idles fine.

[Edited by Gaz2130 on 20 May 2004 at 11:42am]

 

[jabba]

automatic choke mate

 

[Gareth]

Quote: Originally posted by jabba the slut on 20 May 2004

automatic choke mate

pardon? now you have lost me, sorry I dont understand what that means completely, and what effect that has in relation to this problem?

 

[jabba]

just a thought, as u say its fine when warm but sh*t when cold. your car has an automatic choke which comes on when cold startin etc if its bust then your car will stutter and generally be sh*t till the engines warmed up. tbh ive only had my 172 for a monthish so im not bang up to date with their shissnet but its my best guess, ask renault and see what they say...

 

[snoozer]

try a new cold start sensor 8200164249 £10.92 - there pretty common for goin on most of the other renaults. They attach to the n/s of the inlet manifold. If its not that get a diagnostic done on a Renault clip.

 

[Jim.]

Quote: Originally posted by jabba the slut on 20 May 2004

automatic choke mate

sounds feasable

 

[bigmouk]

Quote: Originally posted by Gaz2130 on 20 May 2004

but it only does it when the engine is cold? when the temp gauge reaches the "norm" the car is absoultely fine, idles fine.

[Edited by Gaz2130 on 20 May 2004 at 11:42am]

mine to, from 250 miles (dont recall it doing it before that). done 3000 now and still the same.

 

[Gareth]

yeah, but i am on about the car being REALLY bad, like for example, before, with the famous cold starts (which I have always had), you could drive off and the car would just be sluggish, but would actually drive. But this is something else, basically the car is just near impossible to drive until its warmed up, but without putting my foot on the gas and shaking the car to bits to warm it up, it means i have to wait 10-15mins each time i want to use the car when the engine is cold. Nightmare!!

 

[Gareth]

i think i will have to have a general chat with Renault when i take it in on saturday, and ask them to run a diagnostic check on the cars computer and reset the computer if they can

[Edited by Gaz2130 on 20 May 2004 at 1:00pm]

 

[bigmouk]

does it idle ok when cold? mine idles about 1200 when cold but seems smooth and ok, then drops to about 700 ish when warm

 

[Chad]

When I used normal super instead of optimax It ran like sh*t when it was cold. Very hesitant and lumpy. Was all ok again when I put optimax back in.


[Edited by Chad on 20 May 2004 at 1:30pm]

 

[Gareth]

not sure what rpm it idles at, i can find out though, i basically think the engine software is screwed or a cold start sensor like someone has said, i cant see it being anything else if the car runs 110% when warm. Chad i always use optimax.

 

[Chad]

^^ furry muff then

 

[KDF]

First thing would probably be to get Renault to do a diagnostic on it, no point replacing parts here and there if the computer can tell you exactly whats wrong.

 

[bigmouk]

Any techy guys on here have any ideas what this is down to or worked on similar problem?

I know there are quite a lot of motors on here 172/182 that have the same problem when cold (jerky and sluggish). On mine if you try to hold the revs at say 3k rpm you can feel the car holding back, then accelerate, then hold back again. when warm its fine ??????

 

[KDF]

^^ yep mine does exactly that around the 3Krpm mark too, its all to do with emmision control, it only lasts for a couple minutes, dont really bother me at all.

 

[Gareth]

Quote: Originally posted by mauricewt on 20 May 2004


Any techy guys on here have any ideas what this is down to or worked on similar problem?

I know there are quite a lot of motors on here 172/182 that have the same problem when cold (jerky and sluggish). On mine if you try to hold the revs at say 3k rpm you can feel the car holding back, then accelerate, then hold back again. when warm its fine ??????

mine is REALLY bad though, if i start the engine, and "try" to get it to warm up i cant even rev it to about 1,500rpm without the whole car shaking violently.

[Edited by Gaz2130 on 20 May 2004 at 1:45pm]

 

[bigmouk]

Quote: Originally posted by _KDF on 20 May 2004

^^ yep mine does exactly that around the 3Krpm mark too, its all to do with emmision control, it only lasts for a couple minutes, dont really bother me at all.

It doesnt bother me a great deal, but the bottom line is it cant be right! so there must be something faulty somewhere surely.

 

[BenR]

The 172 MK2 doesn have an auto choke, no injection car has one.

Im thinking its either a coil or the lambda sensors.

The engine is always rough on startup, it has to comply with EURO 3 emissoons regs, which is the same as the EURO2 regs, but doesnt allow the 5 min warmup period. SO the engines have to run very lean at start to warmup the cat. The lambdas also need heat to work and they are self heated to help regulate the mixture. If one of the sensory inputs to the ECU messes up then the engine will run like crap. If one of the sparkplus or coils isnt working properly then itll be passing fuel and the lambda will lean down the engine even more making the engine missfire (lean mixtures lead to misses) and make the cycle even worse as more neat fuel makes it though.

Its hard to diagnose from a computer though.

 

[flash80uk]

that sounds exactly like my problem. i took my car (172 mk1 ) into my loal garage today but they couldnt pinpont the exact problem. Maybe sensor related. They recommended it get renault to look at it, which i will do very soon. The car is just undriveable for f ew mins in the morning. Oh finally got my Eibachs today, will get them fitted soon

 

[BenR]

Could just be the coolant temp sensor aswell..alot of things to look at.

Oh, and there is no coldstart sensor either.

 

[JAY172]

cant think of a commen problem on the 172. the last i heard renault technical was looking in to the hesitation you get about 3000rpm when the engine is cold and new software was going to be issued. mine does the hesitation but only for the first few minutes after starting from quite cold. ill have to check if the latest reprogramming cd covers this problem or not. gaz2123- best let renault have a look at the ecu with clip as your fault sounds quite severe so there may be a fault stored.

 

[tonk_172]

Had my car in with renault this week for dodgy starting first thing.So i left the car overnite for them to try and they ring me up then next day to say the chip reader for the key was not reading the key properly so they replaced it and re-chipped the key .So next morning start the car and guess what would only starts second time so back to the garage.

 

[telford_mike]

Quote: Originally posted by tonk_172 on 20 May 2004

.So next morning start the car and guess what would only starts second time so back to the garage.

starting second time is dead common on a 172. Why worry?

 

[JAY172]

mine occasionally doesnt quite start first time. happens once in a blue moon though so im not even going to bother looking at it.

 

[bigmouk]

Quote: Originally posted by BenR on 20 May 2004


The 172 MK2 doesn have an auto choke, no injection car has one.

Im thinking its either a coil or the lambda sensors.

The engine is always rough on startup, it has to comply with EURO 3 emissoons regs, which is the same as the EURO2 regs, but doesnt allow the 5 min warmup period. SO the engines have to run very lean at start to warmup the cat. The lambdas also need heat to work and they are self heated to help regulate the mixture. If one of the sensory inputs to the ECU messes up then the engine will run like crap. If one of the sparkplus or coils isnt working properly then itll be passing fuel and the lambda will lean down the engine even more making the engine missfire (lean mixtures lead to misses) and make the cycle even worse as more neat fuel makes it though.

Its hard to diagnose from a computer though.





This morning I fired it up and sat there for 2 minutes dead and just let it tick over. Drove away and it way absolutley fine.

I suppose I can live with this every day, probably healthy for the engine also. Would be interested if this is the same for anyone else. Cant be arsed messing about goin to Renault, leavin it overnight and all that kak, and it will probably come back worse than when it went in anyway.