Kjetil1Z

Had a low coolant warning on the Superb today. The coolant level in the expansion tank was ok. Stopped and started the car, and the warning disappeared. I had the same issues with both an Ocativa MK2 and Golf MK IV, and always at cold temperatures (-10 and lower) Is this a known VAG issue?

I may do it sometime soon. It may be that my insurance cover the injector failure. If not, I will just buy a new injector, and change it myself. It seems to be an easy job.

unfortunately no. I was a bit in a hurry, so I did not ask either.

Had the car at the dealer today. Measuring injector quantity showed bad injector on cylinder no. 1.

Have booked next week. I'll give an update afterwards :-)

The car has done 135.000 km. Oil change about every 15.000-20.000 km. I guess this would happen not only on cold engine if the engine mounts was the culprit? I will do a general scan to see if anything shows.

I have a CFFB (2.0 TDI) that when on cold engine makes a strange rattle/tractor sound on medium throttle. Also when accelerating the car judders and feels like it have less power, as if it do not get enough fuel or something. This only happens when engine is cold, and only the first few accelerations. The first that comes to my mind is injector(s). Am I on the right track you think? I do have a genuine VAGCOM cable. Which parameters can I use to diagnose fuel delivery/injectors? Thanks!

Hi, A late update on this. It turned out to be the head gasket. It completely blew on 405 000 KM. I ended ut with scrapping the car.

Thanks for all input. Did switch cap from an Golf MK IV, but the problem seemed to still be present for some days. But now suddenly, I have drove the car for about 300km's and there has been no warnings for low coolant, and the level is ok. I don't know if it in fact was the cap, or if there was some air pockets etc. Where those air pockets came from are unknown for me. I will just drive it, and see what happens. Thanks so far!

Thanks. Nice diagram. Yeah, they do not show all ways, but in this case most people point to compression leak to coolant. Thats why I did try this. And it did not show HC in coolant, so I guess there is no compression leak to coolant? I have no misfire or rough idle, no smoking, no coolant in oil, and no oil in coolant. Also no visible coolant leak (need to check this more). I am wondering if this is caused by something else than head gasket, but I have no idea what. When driving, the coolant dissapears from reservoir. When the alarm goes of, I open the cap to let air out, and the coolant fills up the reservoir to over "min" mark again, and I can drive 20-30 km's before the same happens. I am loosing some coolant every time, so I eventually have to refill.

Took a sniff test now, and it did not indicate HC in the coolant.

Thanks. I bought a sniff test set earlier today, so I guess it will show something.

Thanks for the input. There are no signs of water in the oil. I will take it to a shop to do a comp test as fast as possible. Thanks for the input. As far as I can se, everything looks normal inside the reservoir.

Ok, Thanks guys. Others also says that it may be head gasket, but also crack in engine head or trouble with EGR cooler. Anyway, I did some testing today. At cold engine (3-4 hours after last drive) I filled to a bit under max in reservoir. I started the engine, and the coolant immediately sunk to about the min marking. Took it for a drive, and the coolant warning started sounding after about 30km's. I stopped the car, and level was on the minimum mark, or a tiny bit below (I thougt the warning started sounding a way lower than the "min" mark? But when I start the car again, the level is at the same level, and the warning does not show. I opened the reservoir and the reservoir fills way above the "max" mark. Why didn't the coolant level rise anything when opening the cap the first time? I guess the pressure let go somewhere (head gasket)?

When engine is cold the coolant level is correct. When engine is warm all coolant dissapears from reservoir. When opening the cap the coolant reappears in the reservoir. 2.0 tdi BMM Any ideas?