D5254T (to 2002, Audi) 10 miles to start getting warm

[amazondean]

Hi all.

I have a 1996 850 tdi estate. The car has been well looked after and maintained but i noticed that as the weather was getting colder the car seems to be taking forever to warm up. When i take the kids to school its a round trip of seven miles and just starts to warm up so i decided to replace the thermostat. I took the old one out and boiled a pan of water and checked the old one with the new one. The new one was 87 deg. and the old one was 88 deg. and sure enough the new one opened slightly sooner but the new one also opened alot wider and then closed alot slower. When i put the new one in the car i now find that the car takes about 10 miles to warm up. Even longer than before. Once the car warms up the temp gauge always stays around the centre mark without any problems. The fan never seems to come on either, as the car never gets any warmer than the needle pointing to the middle.

Could there be anything else that might be the problem. I don't believe there to be any air locks in the water system either. Any help greatly received.

[Clan]

a good test for the thermostat is drive a short distance to get some heat into the system say get the needle just off the stop ,, then turn off and lift bonnet . if the top hose is at all warm the thermostat is leaking ... you may have 2 faulty thermostats ...

[DieselDoNicely]

Hi all.

I have a 1996 850 tdi estate. The car has been well looked after and maintained but i noticed that as the weather was getting colder the car seems to be taking forever to warm up. When i take the kids to school its a round trip of seven miles and just starts to warm up so i decided to replace the thermostat. I took the old one out and boiled a pan of water and checked the old one with the new one. The new one was 87 deg. and the old one was 88 deg. and sure enough the new one opened slightly sooner but the new one also opened alot wider and then closed alot slower. When i put the new one in the car i now find that the car takes about 10 miles to warm up. Even longer than before. Once the car warms up the temp gauge always stays around the centre mark without any problems. The fan never seems to come on either, as the car never gets any warmer than the needle pointing to the middle.

Could there be anything else that might be the problem. I don't believe there to be any air locks in the water system either. Any help greatly received.

I changed the thermostat on my tdi last year, the gauge now stays slightly above the centre line and the fan is always on in the summer. I wonder if a cost down has taken place.

DDN

[BillB]

The Tdi is slow to warm up - it seems to be a characteristic. FAR slower than a B230. The heater takes a while......
Regards.

[amazondean]

So is 10 miles about average to warm up for the audi lump. Seems a bit excessive to me. Can other people say how long it takes theres please.

[Bernard333]

My V70 D5 takes 2 to 3 miles and for me even that is too much as during this time it does about 10mpg . If its taking yours 10 miles to warm up then being optomistic you may be getting 15 to 20 mpg during this period and personally I couldnt live with this . I am fitting an electric immersion heater in the sump to pre heat the oil and bottom end of the engine , so far the parts have cost £ 27 but could end up costing more before I have finished and there is no guarantee its going to make a massive difference but I like messing about with the car so nothing lost . What I am looking for is to have 50mpg + from start up and lessen engine wear . Main problem I have found with the D5 is there is not much room in the sump to fit a heater as its full of pipes and diecast webs so the challenge is to squeeze it in and then make an external connection that can withstand the oil pressure . I am not suggesting such an extreme solution would suit you but clearly you need something that will work .

[Grunthos]

glow plug solution

would it be practical to modify the glow plug timer so that the glow plugs would stay on for longer thus improving the warm up time ?

[amazondean]

would it be practical to modify the glow plug timer so that the glow plugs would stay on for longer thus improving the warm up time ?

The glow plugs are there to warm the deisel up before starting, not to warm the engine or oil.

What i dont understand is how can it be different from engine to engine. Surely the only thing that would slow down the rate of warm up is if the thermostat was stuck open which is deffinately not the case or it was opening far too soon and again i have checked the opening temp. The temp needle doesn't even move until a minimum of 7 miles is reached when realy cold and only getting to the centre position by 10 miles or more. Surely an engine is an engine. There must be someone out there that could explain why it could take longer other than air locks which will sort themselves out in the end anyway.

[John_C]

Bernard333 is referring to the D5 which is completely different to the TDI you have in your 850 so you can't compare your warmup times to his.

Cheers,
John

[bvs]

Couldnt be an iffy temp gauge could it ??
My 440 TD had a cool thermostat fitted because it ran warm (before I bought it),after I replaced the fuel/temp gauges it then ran cool...so I fitted an 88deg stat and hey presto...all ok.
I only mention this because I have had instrument/voltage reg probs on all my older volvos.

cheers baz

[dan 244]

Not sure if those 850 TDI engines are anything like the VW Transporter TDI engines, but I have the same thing with the vans, I had a 55 plate and now an 08, they take at least 10 miles to warm up on a cold day, and on very cold day it dosent fully reach the half way point on the temp gauge where it usualy sits. VW tested the last van and said its operation was normal, and the new one being the same has confirmed it, I have considered blocking off half of the radiator on cold days. Also anoying at lunch time if you sit in the van to warm up as it dosent unless it is driven, it will tick over for an hour and not warm up.

[amazondean]

It does sound that maybe this engine does take longer to warm up then. I wander if they over engineered the water ways and made them too big or something causing the problem of taking longer to warm up.

It just makes me think that engine wear is going to be greatly increased, although i've been told they should do 200000 miles before any major work.

[Martin Cox]

At present, with the temperature around freezing, my 1998 V70 TDi is taking about 2 miles or just over 5 minutes to get up to normal temperature. Iv'e never known it take much longer unless the weather is exceptionally cold.

Martin