SPARK / ignition issues, changed plugs to NGK - worse. Was FoMoCo tri tip sparks before Topic is solved

GreenMagicMan · Post by **GreenMagicMan** » 17 Mar 2020, 09:27

Hi
2007 XC90 3.2 6cyl AWD
Approx 176K miles.
Unknown service history.
Car was throwing 3 separate cylinder misfire codes (CEL) and a generic.
Car also has sticking thermostat and code for that.

We got a new thermostat and housing thanks to help with where to get from here

Have yet to install that.
Last night,we replaced the spark plugs AND did the spark plug test tool on each coil.
All coils sparked at similar rates. 3 had a (weakish) orange / yellow spark. 3 had a tiny bit of blue in the spark. None had a strong blue flame. Is that important?
(My superbike shot strong blue flames on all 4 of it's leads with same tester awhile back).
We put in 6 new NGK Iridium ILFR6B spark plugs that shop said was for our specific Volvo.
They have single tip.
What we pulled out were "FoMoCo" LFR6D spark plugs with three tips. They were in bad shape. Excessive deposits, corrosion etc...
....and unfortunately the 4th cylinder from the left (I assume that's cylinder 4) was completely soaked / bathed in oil (!)
I know that's probably a blown piston ring there - or maybe a leaking valve ?? If that, it will not be fixed, for that I would run the car until engine death and scrap the car for parts.
Is it likely a valve cover gasket or spark plug O ring seal could also cause oil on the spark plug?
It IS right behind the oil filler on top of the engine. and there IS evidence of very sloppy oil leaks when it was filled in the past right over that cylinder. Any hope it could be that?
The coil itself was not bathed in oil, or the coil side tip of the plug. It was past the washer where it's inside the cylinder where it was completely drenched in oil. FWIW, shining a bright light into the cylinder revealed a normal looking (not oil sludged up) piston top.

BUT I would like to get the car running the best it can.
On startup it stumbled so hard with the new plugs. it ran horribly, worse than before.

Are the NGK plug / types the issue? My friend spotted one of the 4 wires to cylinder 2 was bare / exposed with no insulation. We wrapped that up with electrical tape - I figured it probably needs shielding. I do have some proper electrical wire shielding - should I install that?

It was late last night, 32F (0 C) and we weren't dressed for the cold and had to stop.

Sad this car is running so bad.

GreenMagicMan · Post by **GreenMagicMan** » 17 Mar 2020, 15:07

The "engineering design" on these cars is a joke. The brake design on these cars suck.

GreenMagicMan · Post by **GreenMagicMan** » 17 Mar 2020, 15:12

Also, there's also some sort of upper motor mount with a cover to the passenger side (front) in the engine bay. Seems there is an aluminum cover that just rattles around and freely moves. Can't be good while running unless this is an idiotic design.

Post by **pgill** » 17 Mar 2020, 17:13

I own two 3.2s and they both run flawlessly

If I were in your position I would start with denso iridium spark plugs

Denso 5344 IKH20 Iridium Power - single fine tip (This is what I use for both of my 3.2's a 2008 and a 2010)

or

Denso 4704 IKH20TT Iridium TT - twin tip (This is what my friend is using and what I will be switching to when I change plugs next)

Both of these plugs have a larger gap as compared to the NGKs that you are using

If you read the Denso literature they developed the Twin Tip plugs to minimize flame quenching

In the later years Volvo switched to the Twin tip or Pin to Pin style Denso spark plugs

The fuel and ignition system in the 3.2 is designed by Denso

Keep it simple get some Denso plugs or if you want to pay more get Denso plugs in a Volvo box.

Good luck

Paul

GreenMagicMan · Post by **GreenMagicMan** » 25 Mar 2020, 20:47

Problem solved!
Thanks you Paul!!!!!!!
We did get the TT Denso plugs you mentioned. It's now back to how it was before... it has it's problems but nothing like the nightmare that occurred when we switched the plugs to the NGKs.
We also kept the .040 gap that the twin tip plugs came with rather than try to gap to stock .028

It was a little surging so to speak, kind of like a harmonic pattern - like a 60 cycle hum - on the idle for at least 5-7 minutes in cold 39F weather. But it eventually settle into a purring perfect idle about 600 rpms.
The tach was not surging during the earlier at startup harmonic surging slight but easily detectable whatever that was.
I'm also going to post up something else here: a strange looking silver aluminum looks like an upper engine mount in the front TOP passenger side of the engine. There is something loose in it that rattles. I have no idea what it's for. I've searched the googles and cannot find what it is. I can say it's not an upper engine mount based on my searches. (I hope this has nothing to do with timing up the upper valves - can't see how it would).

Post by **pgill** » 26 Mar 2020, 11:20

That's great news!!!

Let us know what other issues you fix.

Take care

Paul

XCAndy · Post by **XCAndy** » 30 Mar 2020, 22:22

Good to know... I'll be sticking with the Genuine Volvo plugs. Can't go wrong with the FCP Lifetime Replacement; despite the premium vs aftermarket.

There is a torque rod contained inside of the silver bracket you mentioned. Could be worn out. It connects to the block and the shock tower. Check out Volvo p/n 30680708.

GreenMagicMan · Post by **GreenMagicMan** » 07 Apr 2020, 10:13

Thanks again Paul! Super duper lifesaver.
I've never seen anything like this before in 30+ years of shade tree wrenching...
that spark plug swap completely fixed this car. At least 200 miles and 10x starts - not one single issue. Engine purrs and runs like a top. It's never run like this since it was purchased (well used) in January.

Thanks XCAndy. I am checking that out now. Was just about to post a new thread on it and pics. I can hear that aluminum area rattling around. At first I thought it was very low coolant - believe it or not, it's so loose it sounds like that 'waterfall' low coolant in radiator noise but it's that thingee rattling looser than a baby with cerebral palsy and a broken rattle (I don't know what I meant there apologies).
Here's me pointing to that area / rattle point.

GreenMagicMan · Post by **GreenMagicMan** » 07 Apr 2020, 10:35

I can flick that area around with my fingers - it's so loose. I know that cannot be intentionally engineered that way.
Is that a 'front upper engine mount'?
Is it something else?
I have to assume it's nothing so stupid as an external valve timing thing - that would be impossible.
In the 2nd pic just below my index finger straight down on that light colored aluminum cover, that's where something underneath freely moves and clatters around shifting and under anything but very light acceleration.

So far, I reset the CEL and no more cylinder 1,2,4,5 misfire codes back and engine is clearly running smooth on all 6 cylinders.
I do have to comment on this: why the heck are these cars designed so with the 'armored tank' as I call it front calipers??
I've read and seen now first hand on the other XC90 we have how the inside pads wear out much faster than the outside pads. So in this way you cannot see the pad thickness whatsoever, so you only know the brakes are shot when it's inside bare metal backs of the pads destroying the rotor from the hidden inside (thanks to massive dust shield blocking views from underneath as well).
On all my Hondas inner and outer pads wear out evenly if everything is operating correctly - and if not it's almost always the outer pads that wear out first due to the caliper slide pins sticking so that's a very easy visual ID from outside the car parked looking inside the wheel spokes. It's also easy to see the pad thickness if ya got nice alloy rims on your Honda too.
I think that's a huge design flaw on these XCs at least. I can't figure out if it's just Swedish engineers designing something just to be different from everyone else. And I also can't support making a brake caliper so large and heavy - I just don't understand this logic.

GreenMagicMan · Post by **GreenMagicMan** » 07 Apr 2020, 10:46

Yep. XCAndy you're right. it's that 'upper torque rod' and also called upper engine mount sometimes i guess.
Found great link here how to replace it:
https://andrewpeng.net/cars/2010-volvo- ... eplacement
"We’re interested in part #14 above – luckily, this is an extremely simple part to replace requiring only two tools and about 30 minutes of time! The replacement part number is 31430441 from Volvo and costs about $62 from Tasca."

Not sure what the symptoms of this being shot are aside from noise driving - or what being so loose makes bad / worse aside from noise. But that will get done next during my no work Covid season now.