have a 1998 audi a4 quattro. 5 speed. 170xxx. car is running hot!! i'm thinking it's the water pump bcz heat works great inlet hose is hot with pressure and outlet hose on radiator is cold, so not getting adequit flow. but also i was wondering is it okay to run the green coolant?. because that is what i have in it now. and some people are saying this is no good, which i don't see why it really matters?
please help

 

So the bottom hose off of the radiator is hot and the top hose is cold? I would tend to agree with you in thinking that your water pump maybe shot. Do you know if the timing belt has ever been changed on your car? If this is the original timing belt and water pump, it's time to swap it out.

Also, the green coolant is certainly not recommended for our cars. Audi strictly recommends running the pinkish/purplish G12 coolant. This is somewhat of a taboo topic depending on who you ask or talk to.

 

Here is a good explanation of why phosphate bases green coolant is no good for your Audi:

http://bd8ba3c866c8cbc330ab-7b26c6f3...s_Glycerin.pdf

Short term you will be okay with the cheap green garbage, but if you want your cooling system to work correctly, and your Audi to last another 100k miles , you need to use G12 or new G13 coolant.

Oh yeah, what is the engine type of your A4? 1.8t with a genuine Audi water pump will fail, but if it is a 2.8L V6, water pumps are not likely. If it is a 2.8L V6 you could have a block radiator from running green coolant.

 

Did that solve your problem cause I have an 01 a4 1.8t and we had no heat this was 20 000 kms after having timing belt pump service done by dealer the diagnosis I got from the mech not at dealer said checked everything can only be the pump me trusting this guy had checked everything else he proceeded to chsnge pump gave it back to me with nice heat pumping and the pump he took out from dealer that looks brand new still. That being said first drive afterward up north it started to overheat on me Never had that problem before ?? Then the heat slowly faded away so I start to ask some questions with another mechanic at the shop that did the second water pump and after they did the pump there was still no heat so they flushed the heater core boom heat hoping I wouldn't find out well I did cause I'm not an idiot and got my money back then did the heater core cause that's what I thought was my problem bad coolant flow. Well that fixed the heat issue for now I haven't driven it much cause the coolant light keeps coming on and the temp is still goin up to 100c so I talk to mechanic that put in the second pump and he said it was different then the one he took out that dealer put in and the one e put in impellers where bigger and metal as opposed to dealer one which was plastic. Any ideas please it's my wife's car and she driving me nuts cause she have to drive my hemi and she don't like paying the fuel I've tossed everything at this car over winter ac fan clutch fan all trying to fix the heat and over heatin issue I think I have the heat solved after the heater core but I haven't driven it far and it's summer now so would I be right in thinking that the pump that was swapped is causing my over heating cause it never did it before and I have the pump still and looks brand new ?? Please help I'm so tired I this car right now

 

The pump the dealer put in had plastic impellers?

I would ask for proof about that. I'm almost positive that Audi dealers will not put those into cars. My service manager once asked me what type of pump I put into my 2.7T (plastic vs. metal) and he said that plastic is nothing but trouble in the long run and it's not their standard.

 

Ok well I will call and ask dealer

 

havent got to work on the car yet, but i'm just going to throw in a water pump and cerpentine belt and see what happens. i feel like i might have a little bit of blockage or something. also the coolant lines are not hooked up to my oil cooler. it is bypassed for some reason. i dont know why its like this, the shop i brought it to do it. should i have that hooked back up. wish me luck!

 

Yes you'll wanna have that hooked back up ASAP cause that's what cools your oil down she gets real hot cause of turbo