Help needed, a slowly dying Diesel Auto ZT-T

[jon cee]

Hi guys, this is my first post so please be gentle and bare with me, I might waffle a bit but this car means alot to me. It was my dads before I took ownership , but it seems to have a growing list of problems and each year brings new problems, but he looked after the car so well, I am reluctant to give up on it, and have already put more than triple its value into maintaining it ... not to mention the sentimental value.
so the story begins, ...
My dad owned the Auto Diesel MG ZT-T. from 7 years old , (03reg) it then started having a problem in around 2018... it kept breaking the belt tensioner, he had a few replacements and within a week or two of each replacement, it would break the new tensioner.... after many repeat visits to the garage, who just replaced the tensioner, (without looking for what was causing the tensioner to break),

The they started suggesting other items on the belt system needed replacing ... the only thing on the belt system that has not been replaced is the coolant pump. (which requires the whole engine to come out (or be raised or lowered , to gain access)

So my dad decided he needed a new car, reliable enough to go to work ...
so he bought a vauxall ....
then he went to scrap the car, and I managed to convince him not to scrap it, and to trust me, (his son) with it, and i would trade in my Toyota corolla (which had been the most bland but reliable and cheapest car to run and tax, I've ever owned) for his car instead (at 2.0 ltr diesel, tax is now £300+ per year) ... I had a friend who i had recommended he give a chance at solving the problem, (who he didnt trust, (cos im his son and all his sons friends are wrong uns, lol ) who might be able to fix the problem, but he didnt trust him, while he owned the car) but when I took ownership , my friend replaced the tensioner once, then it broke again within 3 weeks, then he replaced it again under warranty, then it broke again within 3 or 4 weeks, but the warranty company wouldnt replace it again, so he looked into why it kept breaking ... then he found a hint through the grape vine, that a 'modified alternator' might resolve the problem. we had that fitted , and low and behold it stopped breaking the tensioner ...
so that 'modified alternator' solved the problem,I had about 12 months of trouble free driving, then the usual, break pads and discs, tyres, etc (rear brake plates corroded, etc,) .. all these things replaced ... then the diesel pre heater pump broke ... i found one cheap on ebay.
so after the tensioner problem was fixed, all other problems were just general wear and tear ... due to age ... but feeling like I had just about got to the end of all wear and tear , I felt like I was driving a nearly new car ...
so at this point all the things on the belt have been replaced appart from the cooling pump, new discs and pads, etc, bearings, suspension etc, ....

NOW THE CURRENT PROBLEM IS A POWER DRAIN ... a PARASITIC BATTERY DRAIN ... the mechanic I recommended, seems to have got sick of the sight of this car and has said he cant help diagnose a battery drain, and I understand locating a power drain can be very long and laborious, and working under 'mate rates' is another factor putting him off helping ... so My question is ... what is the most common parasitic drain on the MG ZT-T auto ?
an auto electrical specialist, wants £80 per hour to diagnose and cant guarantee less than 3 hours for just diagnosis . (so possibly £240, just to find out what the problem is) ... without actually fixing it.
Any help would be greatly appreciated ... I love this car and it has sentimental value, Its in great condition, but i feel now the electrics seem to be dying, maybe i am throwing good money after bad ...
please help , lol
(sorry for the waffle)
And while I'm typing, would like to say a big thank you to all the contributors on this website, Ive been reading posts all over this site for years, for solutions etc and fuse box diagrams etc, and the renault 5 thermostat inline fix saved me a tun of money . (just wish i read it before i brought the factory thermostat, which now lives in my box of ZT-T bits , lol )
I am just worried, am i letting my personal attatchment to this car over ride common sense ? ... at what point do I say, i've put enough money into this ? .. but then when i think about buying a different second hand car , I wonder if I am just buying another mans problems, and I am pretty sure they wont have looked after their car, like my dad looked after his car

[Mike Noc]

Have you looked at the common causes for parasitic battery drain? If you have a Sat Nav fitted that can cause the problem, the fuel burning heater can also cause a drain by starting up when it shouldn't. On one of our cars it was the cd autochanger not shutting down.

If you are handy with a meter you can try having a go yourself, it is just a process of elimination.

[stocktake]

Hi Jon,
you need to tell people what equipment your car has, one of the big culprits of parasitic drain is the OEM sat nav that if is fitted lives in the boot, then there are some who have found water leaks through the sunroof drains play havoc with electrics. A webasto heater if fitted can also be a culprit and of course the alternator can discharge your battery in some instances.
A good tool for tracing parasitic drain is an Amphound, an electrical device that can tell you what current draw is through individual fuses without disconnecting them.
Good luck

[jon cee]

wow, thanks for the rapid reply ...
I did wonder about the webasto heater, but the cheap webasto pump i bought of ebay, does seem to have an audible clicking , when in operation, but it only seems to pump when it should (in lower temperatures)
funny you mention the multi cd changer, because that is what my mate suggested, straight off the bat, without even looking at it, .... and i have noticed the sterring wheel control buttons for the radio, no longer do what they should, but sometimes they do ... for example, when i try turning the volume up, using the steering wheel controls, it actually turns the radio source to radio, , when i try turning volume down, it turns it up ... when i select mode, it turns off . so some funky things are defo happening with the steering wheel controls ... but this started happening recently , long after the power drain problem arose ... i only noticed the power drain problem, at the begnining of lock down, last year ... it seems to take 5 to 7 days for the battery to drain ... before lock down, i was using the car daily ... so i find it hard to identify what changed to cause the drain ... but the stereo problem only occured in the last month or two

[jon cee]

Originally Posted by stocktake

Hi Jon,
you need to tell people what equipment your car has, one of the big culprits of parasitic drain is the OEM sat nav that if is fitted lives in the boot, then there are some who have found water leaks through the sunroof drains play havoc with electrics. A webasto heater if fitted can also be a culprit and of course the alternator can discharge your battery in some instances.
A good tool for tracing parasitic drain is an Amphound, an electrical device that can tell you what current draw is through individual fuses without disconnecting them.
Good luck

No sunroof . no OEM sat nav ... does have a 6 disc changer in glove box,
i tried the DIY parasitic drain test, (linking an ameter in the negative link to the battery, but appart from the initial momentary peak of 0.75 amps when completeing the circuit . after a few seconds, it settles at 0.36 amps ... so it doesnt even show a drain ... or should i wait longer ?

[stocktake]

found this in a post which is interesting

"there is simple test for a failing alternator diode - set the multimeter to AC voltage and then switch engine on - then apply to the battery terminals -should be no AC current at all- am getting an AC 30 v reading -so looks like a failing diode which can cause battery drain"

and this thread:

https://the75andztclub.co.uk/forum/s...w.google.co.uk

[RogerHeinz57]

So at what rate does the drain run would be one of my first questions. Does it run the battery right down over a day or two, or does it take a number of days without the car being used, The answer to this will assist in various opinions of where the fault may lay, otherwise you may find yourself stripping multiple components down to find no fault, and then move onto the next potential issue based on a whim. However a few suggestions to begin with -
When one of these vehicles (Diesel) get a T-4 diagnostic check, a regular fault that gets thrown up is the Glow Plug Relay issue. This often shows as a fault but offers no other issues.but initself may be causing a drain because of water ingress or general failure, but may still cause a fairly good draw of power. This is located with the engine ecu beneath the windscreen wiper arm on the n/s. Sometimes a central door locking motor can become tired and take a very long time to complete it's cycle.
Also some audio equipment installations can have failures, the highline sat nav system fitted as factory fit can get drowned via water ingress in the loadspace, this will cause many problems which may not be noticeable until the entire audio system gives up and fails totally.
So a few pointers to consider, but again the level of draw-down needs to be estimated and inform the group of helpers to in turn help you.
Finally, you will find there are many places that really dont want to work on these cars, these tend to be oil filter spinner type garages who want it easy and dont use logic in their process of fixing stuff !

[jon cee]

your question is one of my problems .... it very hard to define .. its almost like the drain isnt there some times .... I only noticed it after the car was idle for about a week or more .... during lockdown . I put it down to a dead battery. bought a new one, fitted it, and used the car every few days for about a month or two, then I didnt use the car for about 7 days , then it was dead again ...
but since I realised there is a battery drain somewhere ... its hard to pin point what or where or even if it is there .... I now alternate between batterys , recharging the old battery, while the new is on , and then if i dont drive the car for a few days, I might have to put the old one on ... sometimes the new battery drains in a few days (5-7), sometimes the old battery drains in a few days (5-7) ... there doesnt seem to be any regular pattern .... I would expect the old battery to drain quicker, but sometimes the old battery lasts longer .... I appreciate that might be because of how long ive charged it ... but since trying to diagnose the drain problem, i put both batteries on a 12 hour recharge , using a timer plug... and still sometimes the one battery will last longer than the other ... sometimes its the older battery , sometimes its the newer battery .. which seems to tell me, along with the test i did, where there was NO BATTERY drain, the battery drain might be intermittent ....
generally speaking , if i leave the car unused for 5-7 days, the battery will be dead ... but enough power to open the central locking, but not start the car ...
if i leave the car for 8-10 days, its dead dead. not enough power to open the central locking
but then sometimes, its been dead dead, within 4-6 days , (but that might be because of insufficient charging)
thanks for you help and sorry for the variables . I'm kind of hoping to get a tip on whats the most common things, so i can check those first

[jon cee]

from reading these posts over a few years, Ive heard of T4, but dont know what it is ... I thought that was reference to a contributor ?

[jon cee]

btw ... I've done the plenum checks, and bone dry and clear as a whistle. although even I am wondering if some moisture is getting in the ecu ?