Topnoob

Hi there,

Seeking some assistance from you great people.

My Audi Q5 SE 2.0 TDI Quattro has had some issues over the last month. One day it struggled to start (never had any issues with it) but after two attempts it started and worked. The next day it wouldn't start at all. Got a mechanic (mechanic 1) to come look at it and there was no fuel delivery so we got at the fuel pump and confirmed this seemed to be the problem. Got a second hand fuel pump (I know, I shouldn't of done this) had that fitted, worked for a day then the same thing happened. Contacted the mechanic (mechanic 1) and was told to get a brand new one. Got that.. had it fitted, cleared error codes and it worked fine for an hour into a 40mile drive, when on the way back, doing 70 on an A road and the coil sign started flashing on my dashboard and I started losing power dropping in speed 10mph per 4 seconds where it then finally stopped and wouldn't start again. I got the rac to tow it back home. Had another mechanic look at it and they confirmed the drive belt snapped and there was an issue with fuel delivery so they suggested to change that along with the fuel filter. Done that but the car would've start. Did the diagnostic test on it and it was coming up with crankshaft sensor issue so got that replaced but that didn't make it work either. Concluded that the timing was probably out but the timing belt was still in place. Got a new belt and the mechanic attempted to do this, by hand with the front of the car still on. They were following diagrams and using touch to find the markings which I thought was a bit strange. Tried this multiple times over two/three days (at one point they tried starting the car like 10-15 times one after the other but it wasn't having it, just making a screeching sound). Did a compression test and the compression was very low almost nothing there so they thought the timing was still out. They said they'd order a timing tool kit to insure it's done bang on. At this point the car was taken to a different mechanic (mechanic 3) for a second opinion as the other mechanic was saying there may have been piston damage which would mean I would need a new engine. The final mechanic (3) checked the timing that was left by the second mechanic and it was 6 clicks out or something which led them to check the engine and confirmed that the cylinder head was ruined with loads of pieces flying around in there from it being started so many times with the timing out. I'm now stuck with a huge bill which I accept I will have to pay however, from experience could this have been the second mechanics fault? Or could it have been from when the drive belt snapped and the car slowed from 70mph to 0 over the course of 10-15 seconds. Any opinions would be greatly appreciated!!

Just for reference the car is a 2009 model and has done just under 130k, last service was at 117k 7 months prior.

Thank you

Redd

First off, I'm not intimate with these engines.
But I do know they are "interference" engines. That is, in order to get better efficiency and power, they are designed so the pistons and the valves both occupy the same space in the cylinders. The timing (governed by the timing belt) ensures that both are not in the same place at the same time. WHEN the timing belt eventually slips a cog or snaps, then the pistons and valves lose their brains and yes, lots of expensive stuff gets smashed up. How extensive the damage is, depends on how fast you were going, how often anyone tried to start the car again, how lucky you might be.

With an "interference" engine you must change the timing belt on schedule, religiously, and pray it doesn't fail sooner. That's the cost of a higher performance engine. Last time I checked, Honda also did this, Detroit and Toyota did not.

While you can, in theory, put a borescope in through the spark plug holes to try looking at the damage, the only real way to evaluate it is to take the cylinder head off the engine and start counting pieces. It may need all new pistons and valves, and that's just a ballpark to start from.

Can't say if mechanic #1 was on the nose, or if the belt had already slipped causing the starting problems.
If mechanic number two really did set the timing incorrectly (really, he has to order a tool, because what he has isn't sufficient, but he tried anyway?) it is possible that there was nothing wrong with the timing until he mis-set it. Ouch. You don't say why you went to three different mechanics, or happy you are with number 3, but this point you need to consider a "major engine job" versus the value of the car. And considering how few places stand behind engine jobs, perhaps ask Audi what a remanufactured engine or other options would cost at a dealership. Even if that is the most expensive option.

MurrayA4

Yes at this point there are too many variables.Should always stick with one good competent shop.Anyhow if your problem is in fact a roached engine then your best bet is to locate a good used engine and have it installed.The 2.0L Tdi is a good motor and widely used in Europe ? so you should be able to find a good one and move on. Good luck.