rough idles / spluttering when cold start -0

[EXP0SED]

about 2 weeks ago i went to start the car at around 5am and the temp was at -0, the car started no problem but was idling rough! and spluttering a few taps on the accelerator and it levels out and was back to normal

then again this morning when the temp was the same at -0 the car did the same thing after around 5 - 10 seconds of giving it a little rev the car was back to normal.

this only happens when the car has been sitting over night and its a cold morning

their are no engine lights or error codes stored can anyone think what could be the problem

2.0 TDI on 80k milage

 

[ITzadamZz]

Cold engine mate, this is probibly the sound as theres not enough heat for your catalic converter to be working properly.

Obviously, not too good for your engine and turbo tho

 

[ITzadamZz]

Rough idles would be down to your rev count increasing as your heater needs some form of power/heat.

 

[EXP0SED]

Thanks mate, so would you say its normal and nothing to worry about? my first diesel lol

 

[ITzadamZz]

Yeah, it happens on my petrol. I got quite worried at first too aha..

 

[EXP0SED]

Yeah, it happens on my petrol. I got quite worried at first too aha..

Thanks dude

 

[RUM4MO]

I'd think that its more down to a drop in performance of a heater plug or 2, nothing to do with the cat or cabin heater!

Remember diesel engines are compression ignition engines, so if the fueling and/or compression are not up to spec, or the heater plugs not heating the combustion area up enough, then it will start rough and improve as the internal heat of the combustion chamber increases.

Edit:- failing that, the engine coolant temperature sensor is not giving the fueling and/or the heater plug controller the correct info to achieve a smooth start at all temperatures.

 

[EXP0SED]

I'd think that its more down to a drop in performance of a heater plug or 2, nothing to do with the cat or cabin heater!

Remember diesel engines are compression ignition engines, so if the fueling and/or compression are not up to spec, or the heater plugs not heating the combustion area up enough, then it will start rough and improve as the internal heat of the combustion chamber increases.

Edit:- failing that, the engine coolant temperature sensor is not giving the fueling and/or the heater plug controller the correct info to achieve a smooth start at all temperatures.

where would you start with this mate? new plugs first?

 

[ITzadamZz]

where would you start with this mate? new plugs first?

What Reg is your ibiza buddy

 

[EXP0SED]

What Reg is your ibiza buddy

2010 mate

 

[camelspyyder]

Lucky its not petrol. Those symptoms can be early signs of head gasket failure on a petrol.

But if your glow plugs are knackered and not replaced the starter motor will be the next thing to break, if my experience of driving an old diesel in the Scottish Highlands winter is anything to go by.

 

[ITzadamZz]

Lucky its not petrol. Those symptoms are early signs of head gasket failure on a petrol.

But if your glow plugs are knackered and not replaced the starter motor will be the next thing to break, if my experience of driving an old diesel in the Scottish Highlands winter is anything to go by.

I have a 2016 seat ibiza, the head gasket shouldnt be that worn yet? How can you tell if ur head gasket is going to blow?

 

[camelspyyder]

My petrol Fiat with about 50k on it spluttered on start because water in one of the cylinders was stopping it firing on all 4 (hairline gasket failure). Lots of condensation out of the exhaust, and actually visible water coming out too. After about 30 seconds or a minute it ran cleanly, so I ignored it. That was bad because when it went properly the head was quite badly warped.

I've been in other cars where the head gasket went with no warning at all - once inconveniently in the Mersey Queensway tunnel.

Poor running when cold can also be stuff like poor HT leads, we had an Astra with some morning rough running that the garage couldn't electronically diagnose - chucked new HT leads on and it ran perfectly.

 

[EXP0SED]

My petrol Fiat with about 50k on it spluttered on start because water in one of the cylinders was stopping it firing on all 4 (hairline gasket failure). Lots of condensation out of the exhaust, and actually visible water coming out too. After about 30 seconds or a minute it ran cleanly, so I ignored it. That was bad because when it went properly the head was quite badly warped.

I've been in other cars where the head gasket went with no warning at all - once inconveniently in the Mersey Queensway tunnel.

Poor running when cold can also be stuff like poor HT leads, we had an Astra with some morning rough running that the garage couldn't electronically diagnose - chucked new HT leads on and it ran perfectly.

So you thinking this could be a head gasket issue?

I was leaning towards bad engine temp sensor as it's only happens when the engine is around 1c or below, when the temp is actually flashing on the dash board.

Dont have any white smoke out the exhaust and not alot of moisture coming out either

 

[EXP0SED]

i managed to get a video of it this morning

 

[camelspyyder]

So you thinking this could be a head gasket issue?

I was leaning towards bad engine temp sensor as it's only happens when the engine is around 1c or below, when the temp is actually flashing on the dash board.

Dont have any white smoke out the exhaust and not alot of moisture coming out either

Now I've seen the video yours is more like when we had injector problems with a FIAT JTD. I'd whack some injector cleaner in that, and premium fuel, get it warm then go for an Italian tune up. (Probably not in top gear that'll be too fast ) TESCO fuel was actually the root of most of our diesel rough running issues to be honest.

 

[EXP0SED]

Now I've seen the video yours is more like when we had injector problems with a FIAT JTD. I'd whack some injector cleaner in that, and premium fuel, get it warm then go for an Italian tune up. (Probably not in top gear that'll be too fast ) TESCO fuel was actually the root of most of our diesel rough running issues to be honest.

Thankyou mate, i will give that a go and see how we get on

PS. i have been using Morrison fuel not to sure what the previous owner was using as only had it two month

 

[SEAT Rule]

Hello there,

if your SEAT has done 80k with the original glow plugs still fitted, it'll more than likely be the issue, plus it wouldn't hurt replacing the Thermo Transmitter also known as the coolant temperature switch, as one of the guys has already mentioned.
The ECU won't always log a fault code for a failing sensor, it depends how well it's still working, and whether it's an intermittent fault.

The coolant temperature switch you can test them with a multimeter, at zero 0°C you should see 7000 to 8000 ohms, then at running temperature 85°C to 90°C you should have a reading between 300ohms & 200ohms Basically the resistance should drop down the higher the coolant temperature gets.

From watching your YouTube video the engine struggles to start up, but does eventually get through the rough lumpy running, including the diesel knock that seems to disappear if it didn't then I'd say you have a faulty injector/s, but it does disappear.

White smoke is neat diesel (unburnt diesel) coming out of exhaust, faulty injector/s plus is often accompanied by diesel knock.
On rare occasions it can be coolant being burnt from a cracked cylinder liner, or defective cylinder head or head gasket as mentioned already by a few others.
If it's neat unburnt diesel it'll really smell strong and will linger around in the air, coolant doesn't as it's mostly steam coming out.

Black smoke is over fueling or faulty/blocked EGR valve, or faulty diesel particulate filter.

Hints of blue smoke are oil being burnt in cylinders, whether that's from valve stem oil seals or piston rings, or badly warn turbo bearings / seals.

You can add some fuel additive/cleaner into fuel tank as already mentioned by others, it wouldn't hurt to be honest.
But I still think it's your glow plugs that have seen better days, this happened to my brother's Peugeot 206 a few years back, only had 2-1/2 glow plugs working, put a new set in and it started up first time.

The old glow plugs you can test them by simply using a power probe, or by using a foot long piece of wire (use 1mm to 1.5mm thick wire)

TEST GLOW PLUGS
Put the body (the threads) of glow plug onto the negative (earth) terminal of a battery, then attach the wire to the back/top end of glow plug, other end of wire goes onto the positive (Live) terminal of battery.
The glow plugs should take between 3 to 5 seconds to glow red on the heater tips,
if they take up to 8 seconds to heat up or don't heat up at all (glow red) then the plugs are no good and need replacement with new.

Hope this helps
Si

 

[EXP0SED]

Hello there,

if your SEAT has done 80k with the original glow plugs still fitted, it'll more than likely be the issue, plus it wouldn't hurt replacing the Thermo Transmitter also known as the coolant temperature switch, as one of the guys has already mentioned.
The ECU won't always log a fault code for a failing sensor, it depends how well it's still working, and whether it's an intermittent fault.

The coolant temperature switch you can test them with a multimeter, at zero 0°C you should see 7000 to 8000 ohms, then at running temperature 85°C to 90°C you should have a reading between 300ohms & 200ohms Basically the resistance should drop down the higher the coolant temperature gets.

From watching your YouTube video the engine struggles to start up, but does eventually get through the rough lumpy running, including the diesel knock that seems to disappear if it didn't then I'd say you have a faulty injector/s, but it does disappear.

White smoke is neat diesel (unburnt diesel) coming out of exhaust, faulty injector/s plus is often accompanied by diesel knock.
On rare occasions it can be coolant being burnt from a cracked cylinder liner, or defective cylinder head or head gasket as mentioned already by a few others.
If it's neat unburnt diesel it'll really smell strong and will linger around in the air, coolant doesn't as it's mostly steam coming out.

Black smoke is over fueling or faulty/blocked EGR valve, or faulty diesel particulate filter.

Hints of blue smoke are oil being burnt in cylinders, whether that's from valve stem oil seals or piston rings, or badly warn turbo bearings / seals.

You can add some fuel additive/cleaner into fuel tank as already mentioned by others, it wouldn't hurt to be honest.
But I still think it's your glow plugs that have seen better days, this happened to my brother's Peugeot 206 a few years back, only had 2-1/2 glow plugs working, put a new set in and it started up first time.

The old glow plugs you can test them by simply using a power probe, or by using a foot long piece of wire (use 1mm to 1.5mm thick wire)

TEST GLOW PLUGS
Put the body (the threads) of glow plug onto the negative (earth) terminal of a battery, then attach the wire to the back/top end of glow plug, other end of wire goes onto the positive (Live) terminal of battery.
The glow plugs should take between 3 to 5 seconds to glow red on the heater tips,
if they take up to 8 seconds to heat up or don't heat up at all (glow red) then the plugs are no good and need replacement with new.

Hope this helps
Si

very informative thank you very much! i have currently added a fuel additive to the tank and will test the glow plugs and see what they are like, unfortunately there is no receipts with he car for any work that has been done done their is a good chance they are the original glow plugs