All,

I’ve seen some posts on this previously and just wanted to get some thoughts as a good decade has passed since some of the previous posts were made.

I’ve got a recurring code, P1296, throwing an EML. I’ve replaced the CTS twice, one with an off brand crap one which did not resolve and secondly with a genuine. Still no fix.

The car basically doesn’t get up to 90. When driving, if you’re doing short journeys or sitting in traffic it might creep up close to 90 or even sit at 90 at the lights. Never goes past 90, never overheats. The moment you start driving, the temp drops again and will sit around 70. During my commute which is mostly motorway, I can do a full 45 minutes worth of driving and the car won’t get beyond 60.

Due to the horrific pinch clips on the vacuum lines teamed with me being fairly lazy, I’ve asked the VW specialist I use to replace the stat along with some other suspension work next week. They did clear this EML for me a couple of weeks ago, took it for a drive and said the stat seemed to be opening when it should, fans were coming on when they should etc. They don’t think a stat would throw this error but we’ve agreed to replace it and continue investigating if issue still persists.

In my opinion, I think the stat is opening too early on motorway drives. After a long drive where the car should be up to temp, put the heater on 25 and it will be luke warm. I’m no expert, would love to know other people’s thoughts.

Cheers!

Good practice is to replace the thermo and cts at the same time with genuine parts. You'll then want to fully bleed the system, ensuring there is no air in it. I can go straight out on to a 60mph road and the system is up to temp within 5 minutes.

Other than the above, I can only think of it as being a wiring issues. If you can get the garage to do a scan and check the measuring block, you can go from there and try and hunt down the issue.

Thanks for the reply!

Took the car out today after doing a bleed. Doing some short drives around and about I managed to get it up to around 80, but this took around 20 minutes worth of driving.

Most of the roads by me are long country lanes, national limit. The moment I started going down those at the speed limit the temp would drop to around 60/70.

Still the same really, short journeys or at the lights and the temp will creep up. The moment you’re on the move at a decent pace or on motorways, it will drop right down.

MPG is still around 40 and there’s no running issues.

Thanks again!

Might be a wiring fault to CTS. Check for corosion or broken wires etc.

Alasdair

Thanks for the suggestion!

Can't see any corrosion so going to go ahead and replace the thermostat and go from there. Hopefully this can get sorted, not really wanting to push the car at all without it being a solid 90.

Hopefully its just a bad or wrong stat that was fitted. If a new stat doesn't fix it it may be a broken wire. Get the garage to check the actual temp using VCDS or similar and compare it against dash guage in case its a faulty guage. Another obvious point which I am sure you would have noticed would be is your cooling fan running when it shouldn't. My old Octy used to do the same. Only ran near temp in the summer. In winter never got above 55-60 degrees.

Alasdair

Hopefully you’re right @Alasdair1, I can’t see any evidence of the car having had a new thermostat at any point so seems like the next best step.

As for the fans, I’ll have to do a check myself to be fair and have a listen. I haven’t noticed them coming on from cold, not unless the air con has been left on. Did you ever find a resolution to your issue?

No I gave up as the car needed an MOT that I forgot about and reckond I couldnt do it in time so ended up buying a cheap 1.6tdi to keep me going. I must get onto fixing my old cars when I get time Getting to be a bit of a collection.I have eight of various makes waiting although some are well past fixing but are great donors for parts.

Hope the thermostat solves the prob

All sorted!!

Thermostat has completely resolved the issue. Sits at 90 now, solid as a rock no issues. Runs smooth as and with a handful of bushes replaced it’s a hoot. Haven’t properly given it the beans since I bought it because of it not being up to temperature, so now that I can it’s putting a big smile on my face. I can finally move on to the bodywork.

128k, 05 plate. Plan to keep it on the road for many years to come! Thanks for all the replies. I’ll post a thread at some point with the full journey.

Glad you got it sorted and it was a fairly simple fix.

Alasdair

On 03/06/2025 at 18:52, NewTimer said:

All sorted!!

Thermostat has completely resolved the issue. Sits at 90 now, solid as a rock no issues. Runs smooth as and with a handful of bushes replaced it’s a hoot. Haven’t properly given it the beans since I bought it because of it not being up to temperature, so now that I can it’s putting a big smile on my face. I can finally move on to the bodywork.

128k, 05 plate. Plan to keep it on the road for many years to come! Thanks for all the replies. I’ll post a thread at some point with the full journey.

Do you know what the issues were in the end?

In the end it was definitely the thermostat. Quick and easy fix, changed the car completely!