Juddering engine when cold...

[danregs]

Ok, thought it was coil packs, but have disconnected them one at a time (and tried disconnecting the injectors one at a time) and doesn't make any difference disconnecting any of them... which i find very odd?!

engine judders horrendously when cold and idles incredibly lumpy at around 700rpm...

once warmed up it runs ok but you can feel it's missing every so often. and when cold it jumps on even light acceleration, kinda kangaroo style!

any ideas? if you need any more info i'm more than happy to answer questions, or try anything you can suggest?!

thinking might flush the fuel system with Forte, and maybe disconnect the battery for a while to re-align the throttle body... anything is worth a go?!

could it be lambda probe? coolant temp sensor? MAF?

cheers guys


oh, for info, have just replaced all plugs, and also the two H type coil packs... now got two new "R"s, an L and an M... and didn't make any difference...

 

[STEVEO@CYMRU]

did you check the gap on the plugs , 0.32 standard and 0.28 chipped.
mine were wrong and caused all sorts of problems

 

[danregs]

No I didn't mate. Will give that one a go, cheers!

Any other ideas?

 

[NickT]

did you check the gap on the plugs , 0.32 standard and 0.28 chipped.
mine were wrong and caused all sorts of problems

I think you're missing a couple of zeros, shouldn't that be 0,032" and 0,028"?

 

[sheffboy]

If it's kangarooing a bit, I'd check your dog bone mounting.
I had mine replaced for the powerflex one at service and its cured a similar problem i had with mine. It does vibrate a bit tho

 

[danregs]

cheers nick, yeah will be 0.032 on mine (ps. nice wheels!).

sheffboy, thanks - excuse my ignorance, but where is the dogbone mounting exactly? i presume its an engine mount? is it expensive?

when i drove into work this morning my car was fine! typical! i was all ready to start disconencting the MAF, and then coolant temp sensor to see if it made a difference!

 

[andycupra]

cheers nick, yeah will be 0.032 on mine (ps. nice wheels!).

sheffboy, thanks - excuse my ignorance, but where is the dogbone mounting exactly? i presume its an engine mount? is it expensive?

when i drove into work this morning my car was fine! typical! i was all ready to start disconencting the MAF, and then coolant temp sensor to see if it made a difference!

if its just a when cold issue then i doubt its the dog bone.
But, FYI you are correct, it is an engine mount, located centrally underneath the rear of the engine. Many people upgrade this to as it helps get power down.

There are a few people suffering from lumpy jerky engines when cold at the moment. So you are not alone.

Id say check:
Spark plugs, possibly even coil packs but i dont know how you would check these...).
and throttle body could be cleaned.

 

[danregs]

ok thanks andycupra. will check plug gaps... and how do I clean the throttle body? i know people tend to use carb cleaner... but I've never cleaned a throttle body before so have no idea where to start?! (will do a quick search a minute, but if anyone has a link to a useful thread then please post it! )

 

[andycupra]

ive never done it either, but its something about spraying it in the intake. Ive seen a sip saying have the exhaust downwind as it produced smoke that doesnt smell to nice.

 

[dainott2105]

Im a little worried now, my car is lumpy for the first minute or two on cold start up aswell, but just thought that it was to do with the secondary air pump that i havent got around to fixing yet.
I just presumed that when i drilled out the rivets and replaced them with bolts that the juddering would stop.

Gonna do an oil change so i might get the spark plugs changed aswell. Anyone recommendations folks? Also what u mean by gaps in the plugs (dont mean to sound thick, but i am)

 

[NickT]

... Also what u mean by gaps in the plugs (dont mean to sound thick, but i am)

You said it , try this:

http://en.wikipedia.org/wiki/Spark_plug#Spark_plug_gap

 

[DPJ]

Ok, thought it was coil packs, but have disconnected them one at a time (and tried disconnecting the injectors one at a time) and doesn't make any difference disconnecting any of them... which i find very odd?!

engine judders horrendously when cold and idles incredibly lumpy at around 700rpm...

once warmed up it runs ok but you can feel it's missing every so often. and when cold it jumps on even light acceleration, kinda kangaroo style!

any ideas? if you need any more info i'm more than happy to answer questions, or try anything you can suggest?!

thinking might flush the fuel system with Forte, and maybe disconnect the battery for a while to re-align the throttle body... anything is worth a go?!

could it be lambda probe? coolant temp sensor? MAF?

cheers guys


oh, for info, have just replaced all plugs, and also the two H type coil packs... now got two new "R"s, an L and an M... and didn't make any difference...

Coolant temperature sensor.

 

[danregs]

Coolant temperature sensor.

Cheers mate - sounds like a very confident and definate answer?!

Might be worth going to pick one up from GSF on the way home then. They said they've got loads in stock because they sell a few a week - apparently they are a common point of failure?!

 

[skahigh]

Dan, when you said it "jumps kangaroo style" did you mean up off the tarmac or in terms of suddenly surging forward.

I think people suggested the dog bone on the basis that you meant wheel hop off the tarmac. I took it to mean surging forward, something my car has also been doing a bit of lately when cold. I suspect my coil packs may be on the way out.

 

[danregs]

Yeah, just jumpy acceleration - not actually wheel hop. That really would be fun! After disconnecting each coil pack in turn and it not making any difference, I've come to the conclusion that it's definately not my coil packs. Although, I will be buying a spare from GSF later to keep in the boot!!

When my coild pack died the other week, it was obvious. The car sounded like a flat 4 like in a scooby or an old veedub, and power wise, it felt like I was driving a 1.0L Corsa or something!

If you don't know already, coil packs are about 20 squids in GSF, rather than £30 in the Seat dealership (unless you get club discount or something!) ...and yeah they are genuine VAG ones

 

[dainott2105]

Nick T - cheers for the info, but you could have said that i wasnt thick lol

DPJ - I totally believe you after that answer. Can i hazard a guess that you have had the problem before lol

Have to order myself the sensor then! Presume the sensor is on the rad somewhere? Difficult job to change then?

 

[skahigh]

my car doesnt idle rough particularly but it does surge alot when cold. im 98% sure it is not the coolant sensor on mine that is causing this as i changed it just a few weeks ago.

 

[skahigh]

Yeah, just jumpy acceleration - not actually wheel hop. That really would be fun! After disconnecting each coil pack in turn and it not making any difference, I've come to the conclusion that it's definately not my coil packs. Although, I will be buying a spare from GSF later to keep in the boot!!

When my coild pack died the other week, it was obvious. The car sounded like a flat 4 like in a scooby or an old veedub, and power wise, it felt like I was driving a 1.0L Corsa or something!

If you don't know already, coil packs are about 20 squids in GSF, rather than £30 in the Seat dealership (unless you get club discount or something!) ...and yeah they are genuine VAG ones

dan, are they the bolt down coil packs?

 

[danregs]

no, not the bolt down type mate. but if you get the part number from the modification part no's listed in this section then I can't see why GSF couldn't get them too...

 

[dainott2105]

just been having a look now at Coolant temperature sensors and whats the difference between the green sensor and the black sensor. What has everyone changed to when replacing theirs?


Also anyone recommend some spark plugs?