Sudden misfire. Suspect plugs.

kaneelschep · Post by **kaneelschep** » 01 Nov 2017, 21:43

Hi.

I left home with a full 1500kilo trailer behind the volvo.
And 450km down the road it started to lack power and sounds rough like it misses a cilinder. In higher rpm it feels stronger than in lower. Fuel usage went up.

So i suspect a spark plug died on me. After the long parts uphill i just did.
The ngk iridium plugs are about 50000 to 60000kms old. I dont remember exactly.

Now that i think back, i might have heard some slight misfire a few times in the last month. Thought i heard wrong. Hard to judge sometimes.
Also thought i read a misfire would blink the cel light?
That never happened. But cel is allready always on. So maybe that doesnt help..
The wires are bougiecord and just new btw.

First i thought i drive on till a store is open. Since it doesnt really effect the slow driving that much.
But that would take 4 more hours, wich cant be good.
Plus the heavy trailer..
So i stopped at this raststeatte and going to take a nap between some polish truckers.

In 4 hours a well reviewed car parts store from google maps opens. Where i will get a cheap set of some bosch or ngk copper.
Any recommendations?

Post by **wizechatmgr** » 01 Nov 2017, 22:23

Check the distributor cap & rotor when you wake back up.

kaneelschep · Post by **kaneelschep** » 02 Nov 2017, 00:44

Those were changed with the cables. Very recent. both bosch.
I pulled plug wires in order. The way it runs doesnt seem to change. Quite strange

kaneelschep · Post by **kaneelschep** » 02 Nov 2017, 01:51

the 3rd cilinder is not firing. We swapped the spark plug with a working one and it still is the 3rd. It is firing. Just not getting fuel.
On both lpg and benzine.

kaneelschep · Post by **kaneelschep** » 02 Nov 2017, 04:21

We tested the plug. The injection. They are all good at cilinder3. Yet it doesnt fire.
Conclusion is probably a burned valve.

I took of the benzine and lpg injection plugs for the 3rd cilinder to not flood the cat. And assumed the trip home.
It sucks.. But what can you do..

Oh btw. best garage ever! ! The good man helped me for almost 2 hours from the moment he opened. Reading codes. Using his tools. Trying and discussing all. And then didnt want any money..

Post by **abscate** » 02 Nov 2017, 04:59

Turbos should use the standard one prong plug, and I'm not a fan of the fancy Iridium tips. A cheap set of Bosch coppers is best. Do a compression test and let us know about that valve

Smart move to disable the fuel to that cylinder, how was the power running on 4 cylinders?

kaneelschep · Post by **kaneelschep** » 02 Nov 2017, 08:53

The garage that built in the lpg conversion really liked these plugs. And they were running well.
If we get through this, i am going back to some copper bosch though. This mechanic wasnt too happy about them either.

On four cilinders was not great at all, i can tell you

severely lacking power.
With the injection plug still connected it seemed to run better at higher revs than low, and would actually have some pull.
With the injection plug pulled it just didnt want to get to higher revs. Sounded worse too. Probably something got cut out by the ecu.
Could hardly get up hill. Hanging behind slow trucks.
But i couldnt care less. Didnt want to stress the engine anyway.
And the good car got us safely home again for it.
Great way to spend 16 hours and do 900kms..

kaneelschep · Post by **kaneelschep** » 03 Nov 2017, 14:06

I read in this topic:
viewtopic.php?t=33725
erikv11 had the same experiece that it ran a lot worse when he took of the injector plug than with it stll connected. even though one cilinder wasnt working anyway.
good to know

I drove it like that for 450 km with a 1500 kilo trailer. No happy times.. I am very lucky my wife is a very optimistic person and trusts me a lot.

I have been thinking and calculating... And it doesnt look good for the car.
My clutch was allready weak 100000km ago. By never ever spinning it I preserved the body untill now.
But now its squeeking at every gear change and very weak. I am afraid it will just pop at any moment now.
The sub frame and sway bar rubbers are worn. It needs a new complete distribution and multibelt set.
The pvc could be done. Now the head probably needs a new valve and it would be smart to do valve stem seats since it smokes after idling a few minutes.
And besides that the turbo leaks oil and could be redone..
All that would cost more than some second hand diesel would cost me.
If a shop would do it, probably twice as much.
But if I'd dump the car now, it would be worth maybe 200 300 euro. And thats a big shame.. It would be pulled apart and scrapped.

If I get another car (some diesel) instead of putting the money in the shop, I can leave the volvo on the driveway to slowly take apart myself.
If the whole engine is out with sub frame and all. All those jobs are very accesible.
With a newly done head, clutch, belts etc. It would be as new.. And very sellable. And actually I would like to try that car when as new..

But after that it still has to go..
Pulling this trailer really really sucked with this car. The gearbox and turbo setup are really not made for doing 80m/h under load. especially going up the long hills in Germany kills it.
80km/h is max speed with a trailer. That means in 4 and 5 gear max 2000rpm. So no power at all. And you cant drive in 3rd gear all the time to make the car go in the torque band. The benzine usage would be terrible. What am I saying. It was terrible..

And the only way I can afford the car is on cheap LPG. Wich burns harder and sucks even more for this kind of driving.

Something like a 2000 vw passat 130hp tdi would manage pulling the trailer forever with one finger in its nose while still doing 40mpg..
My family drove a 54kw passat till it got stolen at 350000km. A 66kw passat till 700000km. And a 132kw audi a6 till 450000km. tdi's.
All pulled bigger loads on exactly the same roads half their lives.

Beginning next week it will go for a compression test.. But basicly its simple.. I expect no compression on number 3 because of a valve. It all depends on what the other cilinders say. If they suck too, there is little hope for the car. Cant rebuild the whole engine.

Post by **scot850** » 03 Nov 2017, 15:35

Could you fit a better used engine? How about a P80 turbo diesel? I nearly bought a new one back in the late 90's when still in the UK. Great motor (I think it was an Audi 5 cylinder) and even with the auto it pulled really strong. Unfortunately a 1 year old V70 T5 was for sale at the dealer for almost half price and 10,000 miles. Guess how that decision went.....!

Neil.

kaneelschep · Post by **kaneelschep** » 04 Nov 2017, 05:56

I actually allready checked some volvo 850/v70 diesels on the market.
Saw a v70 with full options, leather and actually heated rear seats

But they are getting quite expensive and mileages start at 400000kms. These cars in diesel were really used as high mileage drivers for mostly bussiness men or builders here. Never as weekend cars

The benzine versions actually too.
Just the more expensive high power models got saved by rich people.

The vw/audi van engine definetely proved itself though. Friend of mind just tuned this same engine out of his audi a6.
To put in his vw transporter. 200hp and very short 5 speed box. Drives like stink.

But I know now very well how much problems a volvo 850 itself can have.

I drove mine for 100000kms since end 2013. And had to change a lot of parts to keep it alive.. Always something new. Never had airco even though I worked on every part but the compressor. 4 interior fans died on me. And I can go on..
And a volvo diesel will never be as fuel efficient as a passat.
If I get something else I will really miss the space in the back though,.. But a passat isnt small either.