2009 Q5 - coolant loss.....

[Richard27638]

Odd. Sounds like massive air lock if no heat to cabin or someone has plumbed it in wrong. Check top rad hose, it should be firm and hot after 5 min idle. Not firm or cool, big air lock.

[Expatscot]

Odd. Sounds like massive air lock if no heat to cabin or someone has plumbed it in wrong. Check top rad hose, it should be firm and hot after 5 min idle. Not firm or cool, big air lock.

I was pressing them when it was idling, prior to the actual test drive.

there are three hoses near the front right corner in front of expansion - basically front passenger corner. One big thick one, and two smaller ones if I remember right. Going from memory now - all three were able to be pressed in when car was idling.

I am away from home for a bit at mo - so cant further test until back.... being away and so busy at times is one reason why all this gets so protracted.

Had considered an air lock but had thought that would have sorted, flushed itself through with the amount of times this has happened - but I dont really know enough beyond doing a DIY service... and its even been years since I did that much.

[Richard27638]

The big thick one (not the air intake)... going to the rad should be hot and firm after 5 to 10 minutes. If not massive air lock / leak. This will boil coolant and eject coolant. Could be another sign of cylinder head problem if engine overheated prior to water pump failure....
I would expect audi garage to diagnose pretty well.

[Expatscot]

The big thick one (not the air intake)... going to the rad should be hot and firm after 5 to 10 minutes. If not massive air lock / leak. This will boil coolant and eject coolant. Could be another sign of cylinder head problem if engine overheated prior to water pump failure....
I would expect audi garage to diagnose pretty well.

cheers, will have a look when I get back to it....

I am hoping it isn't any micro-crack in head, gasket issue.... all that side of it was replaced, repaired, refitted, new gaskets etc. The whole purpose of that job was to make it drivable after the water pump went. (Apparently from when it was all taken apart the damage was minimal).

But this whole episode is beginning to feel like

[Richard27638]

On the positive side if it was OK after repair maybe it is something just come loose. (Was heater working after repair?). If it was OK and now isn't negatively could be cylinder head.
Water pump and cam belt failure is normally terminal to an engine so I do wonder at the 'minimal damage reported.

[Expatscot]

Been offline a while.... computer bricked, sorted now but between that and life hassles just didnt have time.

There is bad news, and bad news.

Got the Q5 into local VAG specialists - they are conveniently close enough to reach without it hitting critical coolant dump/overheat.

Upshot is "Carried out investigation into coolant loss, found coolant boiling over. Cooling fans operating okay. Pressure tested - all found okay. Leak test found exhaust gases in the coolant"

Speaking to the manager after he said, in his opinion, it's not damage from the original incident that required the rebuild - its either some issue with the rebuild (there are few head gaskets for these engines that all look to fit, but unless it is exactly the right one then.....) Or, the head was skimmed during the repair - which whilst common on a lot of cars, should never be done to these engines, and its whether the engineering firm (Redmans) knew that or not - you would like to hope so ffs

Either way I have a nice Q5 I cant use. It would take time, and more money for these guys to take things all apart again to enable a more accurate finger to be pointed at what the problem is, and who caused it... The money angle isnt necessarily so bad, its the time that is the issue. (And then the fact that even with knowing what the problem was because of the backstreet way I went about this I may not have any means of redress anyhow). Plus, there is always the chance it is a micro-crack in the head. Either way I am essentially back at square one...

But, as mentioned, the issue is time - the money that would go into sorting this I am going to have to put into a vehicle I can use for work I can't keep hammering my nice/non-work car on jobs. Its both the amount of miles I cover and needing room in the back I don't have in a coupe. I really need to get something on the road I can work in/from. So its looking like punting this as a non runner (someone in the trade with time and skills will get a decent Q5) - and walking away. Shame, as I really enjoyed the little drive back from the VAG specialist. Its a bloody nice vehicle to drive. Think just need to chalk this up to a 'false economy/life lesson learned'.

[Crasher]

and its whether the engineering firm (Redmans) knew that or not - you would like to hope so ffs

It is why I asked in post 2 and 15 . The wording from elsaWin is "The cylinder heads of diesel engines must not be machined" and this is straight after showing the head being checked for distortion but they don't say why. The reason is the surface of the head is HIP (Hot Isostatic Pressing) treated to prevent coolant loss and if you skim the head, you remove it. The worry is engineers and mechanics don't seem to know although many people get away with it, but some don't.

[Expatscot]

It is why I asked in post 2 and 15 . The wording from elsaWin is "The cylinder heads of diesel engines must not be machined" and this is straight after showing the head being checked for distortion but they don't say why. The reason is the surface of the head is HIP (Hot Isostatic Pressing) treated to prevent coolant loss and if you skim the head, you remove it. The worry is engineers and mechanics don't seem to know although many people get away with it, but some don't.

Yeah... I think you had mentioned it in message after my original thread about the rebuild too...

So essentially I am back at square one... I either go through the repair process again (using a proper under one roof outfit) or I walk away, sell it at is for spare/repairs to someone with the time, know-how and tools.

In view of the time and hassle and the possibility (albeit would like to hope unlikely) of further issues post-repair, again... I am likely to favour the latter option. Shame as its a lovely vehicle to drive and I like it.

[VAG-Abound]

It's not clear that you fully got to the bottom of what was done, and whether that was requested by you or on their initiative. It wouldn't be unreasonable to ask for a clear list as it may help you with discussions with Audi, working out what to do next, etc. If they can give you the ordered and supplied part numbers for gaskets, etc that might show up a possible cause. If you can find a mistake in their work (which may be entirely innocent) they may go some way to fixing things up, whatever that might entail.

[Expatscot]

It's not clear that you fully got to the bottom of what was done, and whether that was requested by you or on their initiative. It wouldn't be unreasonable to ask for a clear list as it may help you with discussions with Audi, working out what to do next, etc. If they can give you the ordered and supplied part numbers for gaskets, etc that might show up a possible cause. If you can find a mistake in their work (which may be entirely innocent) they may go some way to fixing things up, whatever that might entail.

Yes, in principle... that is/would be the case...

However, this was entrusted to a mechanic I have used for over 10 years for servicing, brake changes, wheel bearings, clutch replacement - the usual. All of which have gone without a hitch. He usually does the work on his own drive, or if necessary, gets the car to a mate's workshop. There is no, or minimal paperwork. I cover about 4,000 miles per month in work vehicle so cars have been serviced 4 times a year, and that's a lot of brake changes and general upkeep - so its a bit 'back street', but I have saved a lot. This turn of events is, arguably if you believe in such things, karma coming home to roost.

Mechanic took the head off - arranged for Redman's Engine Centre to do the repair - brought me the head and busted bits that needed replaced - I packaged it sent it off. Redman's Engine Centre did the work, sent it back - mechanic and his mate rebuilt engine with the repaired & new parts. [This whole palaver for one reason or another was spread over 5-6 months].

So, the problem is either; 1. micro-cracks from the initial waterpump/cambelt fail that were missed 2. Error in the repair ie: head was skimmed 3. Error in repair ie: wrong gasket.

It is just going to be a sh*t-ton of hassle and entail extra cost - by the VAG specialist - to do further investigative work which may or may not mean the finger can be pointed accurately & blame laid. And even then there is likely wriggle room that would mean I still have to pay for any fresh repair.

My lesson here is - for all it may cost a bit more, go to a reputable, registered specialist with a nice contractual paper trail for jobs as big as this.... ho hum life goes on... Could be worse, I could be getting shelled in Ukraine.