2001 S60 T5 burning coil issue

rmargoli · Post by **rmargoli** » 12 Jul 2015, 08:35

Helppppp

I own a 2001 S60 T5 for a few years now and with no significant issues untill about 6 months ago

During last winter i accidently entered a small puddle and about 15 minute later the mottor started leaping. My mechanic told me that there are issues with Coil #1, he replaced the coil but the issues continued and the coil kept on burning. At the begining it took a few days for it to burn but later it was happening fast.

Next thing he did was to replaced the main harness that is hooked to the coils. after that, the car worked for 2-3 months (minor leaping) but after about 3 months coil #1 (same coild as in the beggining) was burning again.

At that time he said i had to take the car to the volvo service center for them to hook it to a VIDA computer which i did and the service center told me that the comuter was not OK. I sent the comuter to a local fix shop and they told me that nothing is wrong with it (all singnals are properly working) and in any case, there is nothing in the comuter behaviour that would couse the coil to be burned. I did understand that but in any case i bought another use ECM unit, gave it to the computer shop for it to be programed and instaled it in the car

And... coil #1 is burning again !!!

Did anyone encounter such an issue?
Where can i look for the problem?
Is there anything that can couse a short circuit and the same coil to be burned? anything beyond the harness?

Thanks in advance

draser · Post by **draser** » 12 Jul 2015, 14:01

From your post I am going to presume that the high voltage side is failing. That indicates excessive load which leads to the condition of spark plug. The ceramic insulator needs to be clean, also gap should be proper (unrelated however to the water puddle event). Then I'd check the corresponding ground for that coil to make sure the aluminum landing surface is clean.

Post by **precopster** » 12 Jul 2015, 15:31

As above. Somebody's missing something here. Is the coilpack actually being verified as burned or does that cylinder simply fail to fire?? This could be wiring issue if misdiagnosed where a short takes place limiting output to coilpack #1 and garage is assuming it's burned without taking measurement at coilpack connector.

The coil wiring on top of the motor has common ground for at least 3 cylinders. The spark plug further along the chain can cause burnouts of the coil.

You didn't mention if you are using 9125601 genuine coils or the equivalent OEM Bosch units. Aftermarket coil packs can last a very small amount of time and are correspondingly cheap. Recently I picked up a Valeo coil which wasn't cheap as nothing else was available close by. No name coils to be avoided due to poor materials used.

rmargoli · Post by **rmargoli** » 13 Jul 2015, 04:14

Thanks for the response

The coil my mechanic has been using was always a genuine volvo coil (took a picture and it shows 912xxxx). The coil is actually being burned and even melting so is becoming a failed coiled no dought about that

As i mentioned below, the harness that hooks the coils to somewhere (which i do not know where as i do not have the car's drawings) has been replaced and it took 2-3 months until the phenomena occured again

Ron

Post by **abscate** » 13 Jul 2015, 04:22

If the coil melts it has to be either electrical or mechanical

Check the current draw and resistance on the coil. I can think of how a wiring fault in a loom would melt a coil without a fault so I doubt that's it.

I would suspect a bad spark plug thread letting blow by up into the coil, melting it by heat transfer. Pull the plug and see if there are any marks of gasses on it to check.

rmargoli · Post by **rmargoli** » 13 Jul 2015, 04:34

also, all 5 spark plugs had been replaced 3 months ago

Post by **abscate** » 13 Jul 2015, 04:49

It could be the thread in the cylinder head is stripped or even a bad new plug with a crack. Usually you would notice rough running or a code but it's possible to miss it on a 5 cylinder car

rmargoli · Post by **rmargoli** » 13 Jul 2015, 05:14

I think that the coil was miss behaving even before the plugs where replaced. Could it really be that the cylinder itself could be the issue?

Post by **precopster** » 13 Jul 2015, 06:04

Can you post a pic of one of the burned coils? Is the heat from the bottom end burning through the rubber insulator and going up to the wide area of the coil? Or is the heat/melting at the head where the part number is written?

rmargoli · Post by **rmargoli** » 13 Jul 2015, 06:32

will open and see