ECU boxes must be the last resort

I OWN a 1997 A4 Audi 1,8 manual and somehow the engine started shaking and running roughly, usually when accelerating between 100 and 110km/h. It then died and I discovered a cylinder head bolt was missing, there were oil leaks underneath, no supply from the fuel pump, no fuel pressure in the engine, and no spark to the engine. I suspect that the ECU (Electric Control Unit) box is faulty as the instrument cluster loses the reading on some gauges and the fuel gauge gives false readings. The central locking system is also inoperative. What do you think is really the problem? Is the engine ECU box repairable? How much will it cost for a new unit and for the repair of a defective ECU? - Mokgadi

I OWN a 1997 A4 Audi 1,8 manual and somehow the engine started shaking and running roughly, usually when accelerating between 100 and 110km/h. It then died and I discovered a cylinder head bolt was missing, there were oil leaks underneath, no supply from the fuel pump, no fuel pressure in the engine, and no spark to the engine. I suspect that the ECU (Electric Control Unit) box is faulty as the instrument cluster loses the reading on some gauges and the fuel gauge gives false readings. The central locking system is also inoperative. What do you think is really the problem? Is the engine ECU box repairable? How much will it cost for a new unit and for the repair of a defective ECU? - Mokgadi

MOKGADI, the fact that a cylinder head bolt is missing makes one think that repairs were done to the engine by someone who either lacked experience or didn't care.

That might also explain the oil leaks, although it could simply be seals that have become ineffective.

No fuel supply could be due to a faulty fuel pump, or (more likely) problems in the wiring that feeds electrical current to the pump.

No spark at any plug would point to a defective ignition module. No spark at individual plugs could be due to problems in the high-tension wiring to the dead plug(s).

There is no certainty that the ECU is the culprit. In fact, when I discussed your questions with a technician at a company doing repairs to ECU boxes, and mentioned your suspicions of the ECU, his reaction was: "Audis are not known for blowing their ECU."

I suggest that you first fix the things that you can see. They have to be fixed anyway, even if the ECU does eventually turn out to be faulty.

Only if all this has been done and the engine is still dead should you think of getting the ECU looked at.

Repairs are indeed sometimes possible but expensive. Contact me for the name and telephone number of the Gauteng firm doing repairs to ECUs, if it comes to that.

I still have some questions about the role of residual value and the deposit to which I have not been able to get satisfactory answers from my dealer.

I bought a Toyota Tazz, 2003 sports model, worth about R83000 (garage price) with a R10000 deposit. There was a balloon payment of R16000 on the hire-purchase contract, which was paid to the bank after payment of 54 monthly instalments of R2200.

I asked why the R10000 deposit was not deducted from the R83000 to give a purchase price of R73000, and they said the deposit had nothing to do with the purchase price or lowering the instalments.

Please advise if I was misled or if a lack of knowledge on my part.

Willy

The deposit will not change the purchase price, but it will affect the monthly instalments. The higher the deposit, the lower the hire-purchase loan on which you have to pay interest, and thus the lower the monthly instalments. I would look carefully at the hire-purchase contract signed by you. The deposit should be clearly stated on it and also on the invoice that you received. If it isn't, you should take up the matter with the dealer immediately.

An instalment of R2200 on a loan of R73000 might seem high, but note that there are two things which push up the instalment. Firstly, any extras added on to the contract price, like warranty, insurance or a maintenance plan.

The other factor is the interest rate that the bank charges you.

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