Poor running under acceleration

Post by **subzerocarfanatic** » 30 Jun 2020, 15:19

We finally have started driving the car,today was our first trip where it was more than a around the block test drive like I have been doing.
It seems to drive very well and runs very good except for when we hit a big bump or something in the road,when that happens the light related to the ETM ( electronic throttle module), the ETS dash light blinks on and off for a second or 2 then continues to drive normal once over the rough spot.The other day we took it out on the interstate for a better drive and when getting up the on ramp there is a cattle guard to drive over before getting on,when we drove over it it was so rough the ETS dash lit up for a few seconds and the car died,it started right back up and once on the smooth interstate highway it drove fine.
Now, for the problem we had today.The car done fine when we first started in to our errands this morning,making a few stops along the way,but on our way home it started feeling really sluggish,the more i tried to accelerate the more it would bog out and barely run, there was a funny sluggish sound, almost like a tank full of water downed gas but I know the gas is good it has not been but about a month ago we filled it up with premium fuel.
We stopped at the store and i tried revving it up a bit it just bogged out worse and had a funny like odor,not sure if it is fuel related, if the Cat. converter could be bad or plugged, or has water in it somehow, it has brand new OEM O2 Sensors on it.
This happened once before on a trip to town on a test drive,it seems to do it only do this after the car has been driven for long enough to get good and warm/hot, and then it starts running really sluggish and kinda making a gurgling bogging sound,the more i try and rev it the more it acts up and has a weird smell.
Thought i would ask for ideas before hooking up the vida dice scanner. Oh and the check engine was lighting up on and off while this happened.We let it set for 45 minutes at the store to cool off and then were able to make it home barely,the check engine light was flashing on and off the whole way home.

Post by **subzerocarfanatic** » 30 Jun 2020, 15:52

I wanted to add a few things that have recently been done to the C70 while in the restoration progress.
The MAF was replaced with an OEM BOSCH, new OEM Thermostat and gasket with proper blue coolant, MEYLE coolant temp sensor,new OEM air filter,PCV ( fire trap assembly) was all dis assembled and cleaned well and put back together, fuel filter. New OEM BOSCH O2 sensors, installed a used XEMODEX built ETM from eBay( i was having ETM issues with the original white label one so i installed this one and it updated the software with the Vida Dice and it ran and started fine after that. Replaced the 3 or 4 vacum lines with the red,green,blue,yellow silicone set from IPD that go to the Turbo inlet tube. A new ACDelco Professional AGM battery.Too much to list but the other has nothing to do with the engine running like suspension,brakes,tires,rotors etc.

Post by **misha** » 30 Jun 2020, 16:24

Meyle ECT???
Only Volvo ECT(which is Valeo) or at least Vernet.
Check ECT connector from wiring loom side.
They are prone to corrosion and damage.

Flashing CEL means that engine is misfiring.

Post by **subzerocarfanatic** » 01 Jul 2020, 00:28

misha wrote: ↑30 Jun 2020, 16:24 Meyle ECT???
Only Volvo ECT(which is Valeo) or at least Vernet.
Check ECT connector from wiring loom side.
They are prone to corrosion and damage.

Flashing CEL means that engine is misfiring.

May I ask what is wrong with MEYLE? Not questioning your judgement but I read a lot of reviews about their parts and company history before buying it,I buy OEM Volvo most all the time but I figured this was a simple Coolant sensor and i have bought other parts from them and their parts are not cheap junk,just curious that is all. Thanks for the advice. I know about the misfire ,vida dice says cylinder #3 is misfiring, so i pulled the coil and was amazed at what I found,what would cause this much heat to nearly melt the plug to where i can not unplug it from the coil,the plastic on the coil itself was melted really bad right at the plug,i will show an image,is it the coil itself or wiring?

Post by **misha** » 01 Jul 2020, 01:44

Nothing aftermarket simply doesn't work on these cars...they are out of spec and while you trying to solve the problem you had before ECT replacement...you simply chase your own tail.
ECT sensor on these cars is highly important,like Maf and O2.
It's not just temp gauge sensor...it also sends info of coolant temperature to ecu.

Meyle is good for suspension parts and engine mounts...but only in HD version.
Sensors must be oem.

Post by **subzerocarfanatic** » 01 Jul 2020, 08:30

I understand, that is why my question, the parts I bought from MEYLE like the suspension parts,were MEYLE HD and i was impressed with the quality.I will get an OEM Volvo one.

Post by **abscate** » 01 Jul 2020, 08:32

Whats going on with that coil? It looks like RTV gorped all over it for some reason?

Post by **scot850** » 01 Jul 2020, 11:37

OP said it has melted! I have never seen that before and can only suggest an internal short of some kind. I'd pull the spark plug and have a good look to see what it is like.

Did you replace any of the coil packs? Reason I ask is that I have heard of them shorting out. When I puled some out of a V70 I had a few years ago, they were full of cracks in their casings. One was causing a misfire. I ended up replacing them all, and cleaned the surface where the bolt for them goes through and connects to the head, and the head surface to make sure they were clean. This is the ground and again will cause a misfire if not clean and in good contact.

Misha is correct on the ECT. It is funny how a particular part can cause issues with these cars. It is like the spark plug wires for 98 and older can mostly be Bougicord brand. It must be down to how Volvo designed them to meet certain criteria and aftermarket ones don't manage to be consistent enough to hit the target every time.

For those who have been on this and other Volvo forums over many years we would be rich if we had the $1 for every time the ECT had become a problem due to failure or a bad connection at the plug or bad wiring at the rear of the power steering pump area. The ECT also controls the signal for the cooling fan so making sure this works is very important as these engines don't like being over heated.

Aftermarket parts from the OE manufacturer is generally fairly safe, but even there there are knock off parts packaged to look like brands like Bosch.

I know you have had a lot of challenges with this car, but you are now hopefully very close to a good running car!

Neil.

Post by **subzerocarfanatic** » 01 Jul 2020, 13:21

abscate wrote: ↑01 Jul 2020, 08:32 Whats going on with that coil? It looks like RTV gorped all over it for some reason?

It was melted,never seen a coil do that before!

Post by **subzerocarfanatic** » 01 Jul 2020, 15:20

Neil,I have never replaced any of the coils, I guess I should use only Volvo Coils now that I need to replace them,or at the very least,the one that is melted.Do you know where I can buy the coil wiring harness at,the plug is melted to the coil so I would rather replace the harness if possible instead of splicing in a new aftermarket plug. Should I just go ahead and replace all the coils while i'm at it?