The original Nissan 300zx specialist


During the course of working in the workshop on many Zed`s a few odd and sometimes funny or peculiar faults have been found and dealt with, here are a few I thought may be of interest, more have to be added so please book mark and return.

1) 1 out of 8 ( caliper pistons working! )
A worried Customer arrived at the workshop in a particularly sick zed, the brakes were ....... well.... not! No way could this car stop over 20 mph! and to make it worse an horrendous banging from the front end when attempting to stop was....well... scary to say the least. On investigation we found that only one single brake piston in the front pair of calipers was actually working! the other 7 were seized solid. The offside brake disc was warped by some 7 mm! no wonder it was banging! the nearside disc was wafer thin, all this had taken the toll on the front tension rod`s and the bushes had given up and died.

Removal of the calipers and a week long soak in freeing solution rectified the calipers, cleaned and fitted with new seals they were ready to go, a change of disc`s, pads, brake fluid and tension rod bushes returned this otherwise very nice car back to it`s former glory.

So what had caused it? the pads had been left to go too low and with split dust seals road grime had got in and seized them and with unbalanced pressure across the disc warping was very close behind the brake fluid had suffered localised overheating also the bushes were subjected to excessive load as a result.

Sadly a second hand car sales had supplied this vehicle less than 900 miles earlier! by my estimation the root of the problem was well in advance at this time and the dealers view was to sell the car and not mentioning it another case of......... BUYER BEWARE!!!

2) Safety boost on a non turbo!
Some time ago a customer approached us to look at his non turbo Zed as it was suffering from hesitant pull away , not good in an auto (you can not dip the clutch!) After cleaning the VERY dirty throttle bodies,adjusting the timing and checking the air filter which is all standard stuff the road test proved very disappointing.Although now making clean pull away`s the car felt very lethargic, on return to the workshop an ecu test showed no faults? on a hunch I fitted a logic sensor emulator in the loom to the detonation sensor (same place where some fit the resister) this replaces the stock item and provides a test for the following test drive, the car was transformed in the way it accelerated & cruised, smooth and powerful,it is often thought in cases of non turbo`s that low power is normal, well it is not let`s not forget it is still a 3.0 litre 24 valve car with variable valve timing etc, etc, later a new detonation sensor fitted and a nice car revealed.

Interestingly the problem had been looked at by the suppling garage and the AA and no faults were found? Safety boost on a non turbo? you better believe it!

3) Power steering pipe failure.... 20 miles to the litre! (steering fluid that is)
A worried customer arrived in despair at the high level of power steering consumption! 20 miles to a litre was kinda not right eh? We soon discovered a major leak was taking place as the trail of fluid up to our driveway was very evident.
Not unknown but a little unusual the main high pressure pipe from the steering pump to the rack had a 1 inch split in it,Nissan have this part available as a repair section and is an incredible 127 a quick call to a local hose specialist sonn had the pipe ends removed and a new section inserted for 25 and with higher (better) pressure hose than standard.
It does show to be careful when replacing certain part`s they can often be fabricated at a fraction of the original part cost it`s a case of knowing which part`s though.

4) Loose pulley and cam cover
Interestingly we seem to see trend`s in the problem`s we deal with and this customer was no different, a local garage to him had changed a water pump on his twin turbo and when he collected the vehicle they were very eager for him to pay as they were closing and wanted to go.

Subsequently he found the car to making some very odd and worrying noise`s and as the garage was now closed for the weekend and we were open on the Sunday we had a look.The noise`s from the engine were very concerning and I shut down the car very quickly as I had spotted the crankshaft pulley "wobbling"!!! From below it was found that the pulley bolt was very loose and the metal bottom cam cover was not secured and was catching the wobbling pulley. A tightened pulley bolt and some fresh bolts in the timing case and all was back to normal, amazing how low quality some garage`s are willing to work to.

5) Halfords spark plugs specials!
A customer left his Jap spec twin turbo with us to look at various problems but one thing in particular were the newly fitted spark plugs. Having spent some time explaining in depth to the assistant at the Halfords part`s desk exactly what car and the spec he required spark plug`s for, he was supplied with NON platinum NGK items that were the completely wrong one`s! Now bearing in mind our customer was a new Zed owner he was not sure of the actual plug code . But was concerned enough by the low cost of the plugs supplied he questioned it, but was told they were the correct one`s,

A set of correct plugs and other tuning work resulted in a much happier Zed engine, incident`s like this do concern us and is a warning to all to be absolutely sure of what you are fitting whether it be plug`s filters or whatever, Nissan part`s may seem a but dearer, but then so is an engine rebuild.

6) Tractor quality fuel filter
A customer bought Jap spec twin turbo to us for some general work and we noticed that the fuel filter was NOT standard.
After changing the unit which was well ugly and did not fit in the mounting bracket correctly a part number was noticed and further investigation concluded the filter was from a TRACTOR!! what some people will do to save money, not the present owner I might add.

7) Fuel filter Reverse fitted (by Nissan)
Again a customer bought Jap spec twin turbo to us for some general work and it was noticed that a new fuel filter was fitted but the wrong way around which is clearly marked on the filter body, seems it had been changed recently by a ..... main dealer!!

8) Broken pulley bolt let timing belt slip off!
A customer requested us to check his Jap sec zed following a strange cam belt failure. The car was at the appointed garage by the car dealer who had sold him the Zed.

It apparent that the bottom idle pulley bolt had sheared and allowed the belt to ride off and to destruction, most likely cause was when the cam belt had been changed in Japan the garage had left the failed bolt loose and vibration did the rest....cowboys in Japan also!!!!

9) New rad cap failure
Funny how failure trends just continue to occur? Zed`s run hot we all know this, knife edge maybe? not far from it, this is why a tip top cooling system is crucial.
We changed a rad cap on a customer`s car as part of a timing belt service and bled the system as normal when refilling and all seemed ok, however on the road test the half the content of the radiator escaped from the "new" rad cap, having inspected it carefully I could find nothing wrong, but fitted a new one any how after refilling with anti-freeze (again) and all was ok again?

Some time later I came across this cap again in the office draw and wondered, I fitted it to my own zed and left it in place a day or two..on problem. However on the third day made a call a few junctions down the motorway from where we are located, it was a very warm day and although all seemed ok when I parked up and later returned to the car a big puddle of anti-freeze greeted me.Mmm odd but refilling later and putting the original cap back on all was ok, it does show though that even new parts can be faulty and can cause extra hours of searching for a problem when all the time the new parts you are fitting can make matter`s worse!

10) Safety boost just will not go away
As much as we think how clever the Zed electronic`s are they are not foolproof and the self diagnostic test in manual mode can often be misleading giving all clear code`s when there is obvious a problem somewhere.

Now of course not all parameters are covered, but those that are are still subject to unclear and misleading result`s.

A case in question was a twin turbo in safety boost (reduced performance mode to protect engine when various sensors have failed ) often customers have not owned a zed before and are unclear of how the performance should feel, we see many cars in safety boost and the customer is unaware of it, in fact many have either performed ecu test`s or had it done and got a clear code! Upwards of 4 garages a Boch fuel injection specialist and the AA failed to identify the problem with the AA giving the car a clean bill of health!!!

This then usually result`s in the customer feeling all is ok when clearly to a more experienced zed owner it is not.Often the sensor circuit that is faulty will correct it`s self before the engine is stopped so clearing the fault out of the memory.

Sensor emulator software that we use is the only real method of testing and the ecu self test should be used as a base only.

11) More caliper pistons not working
This particular customer`s car has been to our workshop many times as the owner is very keen tio keep the service history up to date and stick to a maintenance schedule. The calipers were showing all the sign`s of seizing, solid brake pedal, poor braking discoloured fluid Now we usually see this in car`s not used often but as a daily driver this zed was a bit of a puzzle.Coincidentally having had the same problem on a few other zeds we dismantled the calipers and replaced the inner seals and refitted,after changing the system fluid all was working as it should. As no actual fault was found we have concluded that the inner piston seals swell up with age and they grip the piston too hard and restrict it`s movement.Following this we have done the same job again on a daily driver so do check the brake pedal for a too hard feel, almost seems wrong to complain that the pedal feel is solid but do check it.

12) Hesitation and misfiring seems to be a feature of the Z32 engine. When we recently dealt with a poor running zed when cold but ok when hot we knew instinctively that it was typically bad connections which improve when hot.Every one of the injector connectors had green corrosion on them, after a clean and adjust we was surprised to find the engine ran worse!! a more indepth check found that disturbing the loom had cause other connections to break down. After 2 hours of checking and cleaning all connections the engine ran sweet.Heat is the major problem here as everything plastic or rubber goes brittle so be careful when pulling at connectors.

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