20 Most Recent 1988 Audi 90 Questions & Answers

Call a audi dealership ,Ask to talk to one of the people in the service department to help you out, Instead of going buy what everry yahoo tells you out on the steet, Or at the coffee shop,

• You have to make sure the plug is fitted properly. If it's popping out, it is not because of to much pressure, it's because of improper installation. I see it time and time again. Not cleaning the area and preparing the plug accordingly. rust, corrosion, improper installation all lead to the plugs popping out. If you paid take it to someone who will do it right. If this was a home job I suggest a complete Freeze Plug Installation Kit and clean the plug hole completely with sandpaper and see it fits permanently.

Regards, Tony

If it is necessary to remove the heater assembly, the cooling system must be drained before removing the heater core.
When a heater core leaks, a new heater core is installed or the old one repaired.
Heater Housing

• The heater housing is usually under the dash and must be removed to gain access to the heater core.
• Procedures for replacing the heater core vary with the year, make, and model of car. It threfore necessary to consult the manufacturer's repair manuals for the proper procedure for replacement.

The heater housing is disassembled to get to the heater core. Heater Core

• Remove the access panels(s) or the split heater/air conditioning case to gain acess to the heater core.
• Remove the heater coolant hoses.
• Remove the cable and/or vacuum control lines (if equipped).
• Remove the heater core securing brackets and/or clamps.
• Lift the core from the case. Do not use force. Take care not to damage the fins of the heater core when removing.
• To reinstall the heater core, reverse the removal steps.

When the heater core leaks and must be repaired or replaced, it is a very difficult and time-consuming job primarily because of the core's location deep within the firewall of the car. For this reason always leak test a replacement heater core before installation.

It sounds like the starter is spinning but not engaging the flywheel. This could be caused by a few things. One, the throwout is not extending the gear teeth of the starter. If the throwout mechanism is electrical, then maybe that wire is not getting 12 volts. If the throwout is mechanical, then it is stuck. Two, there are missing teeth in the spot where your flywheel lines up to the starter gear. If the transmission is manual, try to roll the fly wheel by rolling your car (in gear clutch in) then release clutch to roll everything to a different position. Look at the old starter to see if the throwout is mechanical or electrical.

http://www.isham-research.co.uk/quattro/wiring/Typ85/index_numeric.html

theres a whole bunch of wiring diagrams on this site, fuses, engine, fuel systems etc give it a go.

had this problem with my 93 90, the fuse for the the cluster would blow when i put it in reverse, turned out it was the wires in the trunk lid where they bend when opening and closing trunk, old wires like to break causing short to grounds and shorts to power, work on these cars 60 hours a week and this is where i go frist when a customer has these problems hope i helped

could be fault valve in cap

There are a few reasons why that can happen, most likely the input shaft to the transmission has too much play or wobble in it from a worn out pilot bearing/bushing, the main bearing is worn out, or the synchronizer keys are damaged or worn out and no longer holding, or the shifter rod de-tents or springs are worn out. The only thing that might be repairable without removing the transmission would be worn out shifter de-tents or springs.

There are several for sale on e bay. Should be around 40 to 75 dollars. Besides standard auto tools(spanners ,socket set ,drivers etc. You will need a clutch alignment tool. Hope this helps.

This is likely just worn out motors. I'm surprised they lasted this long. Many motors will work,but won't move once window pressure is placed on them. Most wear out after 10 years. There should be a relay, Not sure exactly where on this car. I will try and located a free owner's manual. You can get free repair manual for your car at autozone.com with free registration. I don't believe they have the relay in the repair manual that i've seen.

either a rear main tranny seal or the pan gasket. needs replacing

Electronic fuel pumps hum. That's pretty normal. It's always a good idea to periodically replace the filter.
First, check your battery cables. Are they frayed? Are they corroded? Are they loose - both where they connect to the battery and where they connect to the block (negative cable) and starter (positive cable)?

If the battery cables check out, have your ignition system and charging system (which includes your alternator and belts) tested by a mechanic.

If these check out, have your vacuum system tested for backpressure or low pressure.