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I have a 2013 Q7 TDI, and noticed a coolant smell which I figured was coming from the valley. Poked my head under the hood today, some more hoping to see about where and saw it streaming from the top side. Curious how difficult a repair this would be? Not overly concerned about changing out the hose, but what I would have to do to make sure no air was in the system.
Anytime you crack open the coolant system you are gonna have to bleed air from it. If you are close to being due for the coolant replacement anyhow (due every five years), then it makes sense to perhaps run a cooling flush, drain it out, repair the hose and refill the system using standard method /vacuum fill, etc. There's good videos online on how to do it, and threads on here discuss also. It's not difficult to refill the system correctly. I'm sure it'll be more trouble to replace that hose. The part # is on it, btw.
Mines got a pinhole leak in the radiator core, but it's a very slow leak. I'm getting ready to swap that bugger out and possibly some other old, beat-up heat exchangers while I'm in there...jolly good fun.
Thank you about 3000 miles ago I had the engine out reseal, so I think my coolant is relatively new. I guess I will need to research how to bleed the coolant on the Q7. Any special tools you would recommend or do I need the Ross tech computer software?
I can't really tell what hose is the issue in the photos. But, it seems to be high up, as that looks like it is over the left (driver side) head. If you can minimize loss, I'd just put it together and run it, then top off the fluid based on its level in the tank. if you lose more and it warrants adding some from the start, pull the bleeder screw in the top of EGR cooler (you can see it on the top, right side (passenger, left as you're looking at it) first, then add more coolant to the tank until it starts dribbling out there. I have never had issues with that method, though I agree with Prestige that the "proper" method is using vacuum.
I can't really tell what hose is the issue in the photos. But, it seems to be high up, as that looks like it is over the left (driver side) head. If you can minimize loss, I'd just put it together and run it, then top off the fluid based on its level in the tank. if you lose more and it warrants adding some from the start, pull the bleeder screw in the top of EGR cooler (you can see it on the top, right side (passenger, left as you're looking at it) first, then add more coolant to the tank until it starts dribbling out there. I have never had issues with that method, though I agree with Prestige that the "proper" method is using vacuum.
Thank you , if you have some time, would you be able to take a photo and identify the bleed screw you are referring to?
After getting the system back together, pull the screw out to let the coolant to settle down easily, then put a rag or other absorbent material around it before filling from the tank cap. Let it dribble a little once full to get as much air out as possible. I then take mine for a short test drive to bring the engine to operating temperature and put the interior heat on HI. If it is blowing warm and is stable at operating temperature, you're good to go.
Thank you I appreciate the reply, I will start ordering parts. Would concentrate or 50-50 coolant mixture be best?
edit. I ran down the part number 4L0122447D and that part retails around $580-$600 for a hose online. When I called the local dealer, they had it for $750. I could probably cobble something together for a whole lot less. I do have a fidelity warranty with a $500 deductible so I guess I’ll suck it up and bring it in and have it done.
Does that seem logical?
Last edited by Smiledr996s; Feb 18, 2025 at 12:43 PM.
Dang, definitely use the Fidelity warranty, and look around in engine valley for coolant/oil pooling in the engine valley bottom, or if the rear main seal is leaking...any oil leaks at all, etc. I'd stick a probe or scope down in the engine valley...go fishing for existing leaks you may not be aware of as yet. If it's going into the shop, then get some good work done for your deductible.
Well. I definitely will need to invest in a good scope. I did have the engine out reseal about 4000 miles ago. And when I took it to an independent for drive line fluid changes they notated a slight leak from the turbo to the downpipe. Not sure if they ever separated when they drop the engine so I will try to claim that and maybe they will find something else
The fortunate thing is the policy excludes the the coolant hoses however, since this one has a metal and plastic parts, the representative said it should be covered if it was just premature failure. So I will just suck it up for the $500 deductible and keep my fingers crossed that it is. I’m still surprised that they would have such an expensive part for a coolant line. Also I find it strange that it is leaking from the plastic or metal portion.
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Found my coolant leak
