Tech

Ah, well done finding it

Hi Iain, this depends which top suspension bush exactly they have advised, there are quite a few suspension bushes, top and bottom! If it is the top strut bush than you will have to remove the suspension leg and will require a spring compressor to tension the spring so you can remove the top bush and bearing assembly. However, if it is a different bush they have advised, the job could be much more simple. Tech

Sometimes roadside assistance guys can make life very hard for dealership Technicians, erasing fault codes we need to see, creating ones that shouldn't be there etc, some are good though. Glad your car is back on the road. Tech

Welcome to the forum, nice car Tech

I have frequently seen drive belts routed to the wrong side of idler rollers, it sounds like that is your problem to me. A clicking when accelerating on full lock defiantly sounds like a CV joint worn. Tech

Did you have any luck Mike?

Iain, you can check if your thermostat is stuck open by feeling the radiator hoses from a cold start. If they are warming up before the car has got to normal operating temperature, then the thermostat is defiantly stuck open. In your case, it is safe to assume it is anyhow really. As for the 'mayonnaise' in the filler cap, this is indeed water mixing with the oil. However, this is commonly caused simply by condensation inside the engine in cold weather. It happens mostly on cars that do shorter journeys as oppose to cars that travel long motorway distances daily, as the car does not stay hot enough long enough for all the moisture to evaporate. It is nothing to worry about in this case. Head gasket failure is not common on Audi engines, I have never witnessed a leaking head gasket on an Audi. Tech

Owners of old 1.8T engines may have experienced problems with these (first generation TT etc). However, on modern Audi's, the part looks much different to this

Hi Mike. Remove the front ashtray insert (the part you remove to empty the ashtray). Under there you will see a black cover with a small lip allowing you to carefully pry it out with a flat screwdriver. Once removed you will see a button that can be pressed. Press this button and hold it down whilst moving the gear lever to position N. Make sure the Q7 is recovered on to a flat bed truck, not towed with any of its wheels on the road, as this would damage the gearbox. Tech

There is no diesel pump as in the sense of the old 'distributor' pump like the original 1.9 TDI or 2.5 TDI has with the immobilisation ECU built in. In a PD (unit injector) engine you have: A simple electric lift pump in the fuel tank that supplies 3-6 bar up to the engine. A 'tandem' pump on the gearbox end of the cylinder head, driven by the camshaft and supplying the injectors with 10-11 bar of pressure The unit injectors themselves, driven by their own cam lobes and delivering up to 2000+ bar final injection pressure. So effectively six pumps altogether with three pressure stages. None of these need coding. Tech

Hi Iain, Glen is right, you'd have to be pretty confident you knew exactly what you was looking at to take that job on. Don't forget the timing belt has to come off just for a start. What gives you the impression the head gasket is at fault? If you was to remove the cylinder head to replace the gasket, it may be worth taking it to an engineering company to have it pressure tested whilst it was removed. Tech

Hi, its nice to have an A8 owner on here. Good choice of motor!

Welcome Ken.p, The Technik gets plenty of kit as standard anyway, it will look much improved with going for the exterior light upgrade too. Hope you enjoy it!

Great news! What was causing the problem?

Ha, yeah Batman is probably right :) Its most likely to be an internal leak into the EGR cooler or an external leak around the oil cooler area. Either way, get it taken to the dealers and fixed while its in warranty. If the warning message is on all the time, don't even bother trying to look at it yourself, phone Audi assist up, they'll take it in for you and most likely leave you a car to use to save you the hassle of being without one. The phone number should be on the back of your tax disc holder. You can't use the car with the coolant warning on, you could do the engine a lot of harm. Let me know the outcome! Tech

It needs looking at Matthew. Is your A7 not still under manufactures warranty (3 years/60,000 miles)? The coolant expansion tank that Glen has refered to is in the right of your engine (looking at your car from the front with the bonnet open). It is an oblong shaped bottler with pink liquid in (or not as the case may be!). Overheating is not a common fault on an A7. I have seen a case of coolant loss on the 3.0 TDI 3rd generation engine as fitted to the A7 though. Just out of interest, what engine is in your car? TDI or TFSI?

Right OK. Sounds like your a pretty competent DIY mechanic then. Check the values as I stated before at the lambda before cat and ignore what I said about lambda after cat. Let me know if anything looks unusual. Have you tried compression testing it? Failing that, I think thats about as far as I can go on a forum without actually seeing the car in the flesh so to speak. I hope something shows up for you. Tech

That should be fine, I'd like to have seen Halfords fitting that for £6.99 when they realised how much of a job it was!

Yeah sure, the lambda value should be between 0.95 and 1.05. The short term fuel trim should not be going out of +/-25% band. The long term fuel trim should be 0%. The lambda probe 1 should be fluctuating above and below 450mV constantly and probe 2 should be 450mV providing the cat is doing its job right. If probe 1 is constantly going above 450mV the engine is running too rich, if it is constantly reading low, the engine is running too lean. Rich running could be caused by a leaking injector, fuel pressure too high, blockage in intake etc. Lean running could be caused by a blocked injector, misfire, unmetered air entering the intake manifold via a split breather, dip stick tube etc. There is of course a chance it may not be an electrical fault at all, and could be in fact a mechanical fault like worn cam lobes for example (which might sound mad, but I have seen this on a few engines in the past and it always catches people out). Let me know how you get on. Tech

scottisha3, Have you checked the things I mentioned in my above post? I know you mentioned there are no stored fault codes to go on, but it would be ideal to read the engines measured values to see what the fuel trim and the oxygen sensors are doing. Also have the fuel pressure checked as close to the fuel rail as possible, both on idle and under throttle. I know you won't want to hear this, but most of the parts you have replaced already (spark plugs, leads, coils etc) were never going to cure the symptoms you have described. It sounds like your mechanic is clutching at straws and replacing stuff hoping for the best. Check the things I have mentioned before replacing anything else. Tech

Off the top of my head I think the full door panel trim needs removing, then the armrest can be unscrewed from the back allowing access to the window switch which is clipped in and removes downwards. Tech

If the drivers information display has gone off altogether it will probably need a new instrument cluster. You can try disconnecting the car battery negative terminal for half an hour though and re-connecting it. This is a simple painless job and can sometimes bring them back to life. Tech

My guess on that one would be a breather issue but if you have replaced the breather pipes I can't say. Have you checked to make sure the dipstick tube is not broken at all and the seal on the oil filler cap etc? If you have access to a fault code reader it would be an idea to check the voltage readings of the oxygen (lambda) sensors and also check the fuel trim. I would defiantly say this is one that needs diagnosing properly as it sounds like you are wasting money by just replacing parts on it. Tech

Only two problems with the 2.5. Fuel pumps if poor quality diesel is used and camshaft lobes on some of the earlier engines wore prematurely due to a case hardening issue. The camshafts were modified on later engines but I can not remember the change over production date. Generally its a good engine

Hi vw754, I'm guessing this is a Q7 not an A3 TDI? If so: 1. It sounds like your battery has had it I'm afraid, either that or you have a slight long term current drain, but the former is more likely. You should not try to remove the battery to charge it, instead you should use the battery charge/boosting terminals under the bonnet. They are located to the right as you stand in front of the car looking under the bonnet. The live has a red cap with a + mark which you need to flip back, the earth is a plain terminal located close by. The battery is located under the passengers seat so it is a pain to get to. It is also advantageous to charge the battery 'in situ' as it allows the energy management to monitor the current absorbed by the battery from your charger and thus recognise the charge state of the battery. 2. Your right, it is not normal. It sounds like the tailgate lock motor has just about had it. Is it closing OK? Is it an electrically operated bot lid? 3. You will find the tyre pressures on either the edge of the drivers door, the inside of the lower B-pillar with the drivers door open or the inside of the fuel flap, depending on the production date of your car. Although, they sound like unusual size tyres to me, are they aftermarket wheels? 4. The brake fluid reservoir is located on top of the master cylinder. Open the bonnet and you will find a flap on the drivers side on the black trim that runs the width of the car between the bulkhead and the bottom edge of the windscreen. The fluid reservoir is under here. Tech