3.sl0w Ranger mystery

[Joe Walsh]

I need some help on diagnosing a problem that I'm having with my 160,000 mile 3.0 V6 automatic 1999 Ranger.
My daily driver Ranger started to get a noticeable misfire and, after more miles than I expected, the CEL finally came on.
Pulled the code: P306 - #6 misfire.
OK...simple enough. It was getting near time for a plug & plug wires change anyway.
Plug #6 was a little wet and the porcelain was dark....not light beige like the other 5 plugs.
After installing new Motorcraft plugs & wires I still had a #6 misfire and, eventually a P306 CEL code.
Installed a new coil pack....same problem....misfire on #6.
It starts up and has a slight miss which goes away once the truck is warmed up, but under heavy load it misfires pretty badly.
Then I checked the coolant and it was very low, plus was rusty brown. (I change the coolant regularly and it has never looked this bad before.)
Refilled the coolant and checked after a few trips:
Uh Oh....The truck is consuming coolant, but there is no smell, no leaks, no white smoke from the exhaust.
Pulled #6 plug and inspected....it doesn't look too bad and was not wet.
Next I did a compression check and all the cylinders read between 144 psi and 160 psi.
Cylinder #6 shows a healthy 154 psi....WTF!?
I was certain that I had a cracked head or blown head gasket.
Before I pull the top end off....any ideas on what else could cause this?

[Blown3.8]

Water going in the oil? Check the vacuum hoses.

[Mike M]

If you know any shops with a exhaust gas analyzer, have them put probe about one inch away from the top opening of the radiator after you remove the radiator cap. Run engine (make sure thermostat is open). See if the probe is picking up any HC-Hydrocarbons. Don't let probe tip touch the coolant, like I said about an inch away from the coolant.
There should be zero HCs, I have diagnosed a lot of head gaskets that way. I have seen anywhere from 40 to 400 HCs on some engines.

I don't recommend the dye system that goes on top of the radiator. It works the same way, the dye changes color in the presence of HC, but I have had some false positives with it.

[Mr. Man]

Go buy a Frontier and be done with it:D

[Joe Walsh]

Water going in the oil? Check the vacuum hoses.

Nope...oil is clear and golden yellow....looks fine.


If you know any shops with a exhaust gas analyzer, have them put probe about one inch away from the top opening of the radiator after you remove the radiator cap. Run engine (make sure thermostat is open). See if the probe is picking up any HC-Hydrocarbons. Don't let probe tip touch the coolant, like I said about an inch away from the coolant.
There should be zero HCs, I have diagnosed a lot of head gaskets that way. I have seen anywhere from 40 to 400 HCs on some engines.

I don't recommend the dye system that goes on top of the radiator. It works the same way, the dye changes color in the presence of HC, but I have had some false positives with it.

I could actually smell what seemed like combustion odors in the coolant reservoir tank when I opened the cap.


Go buy an ECOBOOST F150 and be done with it:D

There....fixed it for ya!

And you are right....I don't want to pour a lot of money into this (underpowered, disappointingly poor MPG) pick up.
It's frustrates me that the new 3.7L N/A V6 puts out more than double the HP and 100 Ft LBs more TRQ.....plus it gets significantly better gas mileage than this turd Vulcan 3.0 V6.....:mad:

[jimlam56]

Nope...oil is clear and golden yellow....looks fine.



I could actually smell what seemed like combustion odors in the coolant reservoir tank when I opened the cap.



There....fixed it for ya!

And you are right....I don't want to pour a lot of money into this (underpowered, disappointingly poor MPG) pick up.
It's frustrates me that the new 3.7L N/A V6 puts out more than double the HP and 100 Ft LBs more TRQ.....plus it gets significantly better gas mileage than this turd Vulcan 3.0 V6.....:mad:



I know what you mean about the 3.0 Joe. My 03 Ranger can't get out of its own way. But it has been an uneventful 240kmiles so far. And I can't replace it with anything as no American manufacturer makes a truck that small anymore. I like to be able to get something out of the bed without climbing into it.

[fordmike65]

Not that this would explain the coolant consumption, but what about an injector? I've had a few that would cause a misfire condition.

[EMAS]

The Vulcan of that era is known to break valve springs which can occasionally still show good compression but cause a miss. They also like to leak coolant at the timing cover to block gasket.

[cougar9150]

Ignition issue sounds like the camshaft synchronizer may be taking a crap on you. Could just be the sensor but I had to replace the whole synchro unit on my 99 4.0.

The coolant sounds like it could be the infamous cracked head issue. I know on the 4.0 it's a common issue that the heads will actually crack/split between the intake an exhaust valves. This also happened recently to my 4.0 and I was basically dumping coolant out my exhaust. All the plugs on the side with the crack would look like crap after only a few days and would start causing hesitation and misfires.

The ranger station is good site with tons of info just don't expect quick or helpful responses if you start a new thread.

Sent from my SPH-D710 using Tapatalk

[Joe Walsh]

I know what you mean about the 3.0 Joe. My 03 Ranger can't get out of its own way. But it has been an uneventful 240kmiles so far. And I can't replace it with anything as no American manufacturer makes a truck that small anymore. I like to be able to get something out of the bed without climbing into it.

I hear you Jim!
I really don't want a truck as big as the F150. The Ranger is a perfect size pick-up for how I use it.
Just wish they had offered them with something besides the archaic cast iron boat anchor V6s.

:hmmm: .... I do have a complete 5.0L with a 5 speed from my '85 GT Mustang sitting in the garage, but it would be a lot of work and additional $$$$ to drop it in the Ranger.
Plus that combo would quickly frag the 7.5" rear and overpower the little brakes on the truck....:burnout:....:drive:



The Vulcan of that era is known to break valve springs which can occasionally still show good compression but cause a miss. They also like to leak coolant at the timing cover to block gasket.

No visible external leaks of coolant...especially considering how much coolant it has been eating.


Ignition issue sounds like the camshaft synchronizer may be taking a crap on you. Could just be the sensor but I had to replace the whole synchro unit on my 99 4.0.


The coolant sounds like it could be the infamous cracked head issue. I know on the 4.0 it's a common issue that the heads will actually crack/split between the intake an exhaust valves. This also happened recently to my 4.0 and I was basically dumping coolant out my exhaust. All the plugs on the side with the crack would look like crap after only a few days and would start causing hesitation and misfires.

The ranger station is good site with tons of info just don't expect quick or helpful responses if you start a new thread.


Yep....just replaced the entire assembly with a Motorcraft unit from RockAuto a few months ago when it started to squeal at high rpms.


I'm thinking a cracked head also :mad:....
just can't figure how it holds such good compression....:dunno:

I posted on the Ranger websites....but as you said....no responses.

[jimlam56]

I too have contemplated the 5.0 route as the truck body and interior is in perfect shape, but as you say everything else would have to be upgraded to accommodate the increase in power.
What I'd really like to do is drop a little diesel into it!

[Joe Walsh]

I too have contemplated the 5.0 route as the truck body and interior is in perfect shape, but as you say everything else would have to be upgraded to accommodate the increase in power.
What I'd really like to do is drop a little diesel into it!

Yes...A small 2.5L inline 6 turbo intercooled diesel would be a dream!
Stump puller and 30 mpg....:banana:

Heck...I'd love to put that Ecoboost 2.0L into it and gain 100 HP and 75 Ft-Lbs of TRQ.

This weekend I'm going to pull the cylinder head and check out what is wrong with it.....:shake:

[jimlam56]

Yes...A small 2.5L inline 6 turbo intercooled diesel would be a dream!
Stump puller and 30 mpg....:banana:

Heck...I'd love to put that Ecoboost 2.0L into it and gain 100 HP and 75 Ft-Lbs of TRQ.

This weekend I'm going to pull the cylinder head and check out what is wrong with it.....:shake:

I can't imagine the Ecoboost in the Ranger, it is way more than I can handle in my Focus ST. It's almost too much power. especially for FWD.
I wonder if the 2.0 has been used in RWD applications?

[fastblackmerc]

I just got my son's 1999 Ranger - standard cab, 3.0 and 5 speed.

Mileage: 162+K

A/C doesn't work and either the blend door or the blend door actuator or both are bad. Other than that there is not much wrong with it. Took a week of disassembling the interior, cleaning and reassembly to get it decent inside. Had the windshield replaced due to a crack across the entire windshield. No power windows, no power door locks.

A good tune up, oil change, cooling system flush, new radiator cap, some vacuum hoses replaced, battery terminals replaced, new wiper blades, new headlights and HID conversion. Replaced the OEM speaker with the take outs from the MM, waiting on a new stereo ($28.00 / free shipping).

Not bad for a beater truck. Gets about 17 - 18MPG - local driving - regular gas.

[Joe Walsh]

OK.....'Good' news is that it was a blown head gasket and not a cracked cylinder head.
I still cannot figure out how cylinder #6 held such good compression when I checked the engine's compression.

Cylinder #6 looks a little wet:

http://i984.photobucket.com/albums/ae326/JoeJWalsh/IMG_5662_zpsfc4b8eea.jpg (http://s984.photobucket.com/user/JoeJWalsh/media/IMG_5662_zpsfc4b8eea.jpg.html)

You can see where the leaking coolant 'steam cleaned' a section of combustion chamber's carbon build-up:

http://i984.photobucket.com/albums/ae326/JoeJWalsh/IMG_5664_zpsc44bcb74.jpg (http://s984.photobucket.com/user/JoeJWalsh/media/IMG_5664_zpsc44bcb74.jpg.html)

Blown head gasket:

http://i984.photobucket.com/albums/ae326/JoeJWalsh/IMG_5667_zpscbeeb96a.jpg (http://s984.photobucket.com/user/JoeJWalsh/media/IMG_5667_zpscbeeb96a.jpg.html)

http://i984.photobucket.com/albums/ae326/JoeJWalsh/IMG_5668_zpse81de08e.jpg (http://s984.photobucket.com/user/JoeJWalsh/media/IMG_5668_zpse81de08e.jpg.html)

I guess that I should not run that 200 shot of 'NAWZ' anymore....

http://i984.photobucket.com/albums/ae326/JoeJWalsh/IMG_5669_zps519b07ae.jpg (http://s984.photobucket.com/user/JoeJWalsh/media/IMG_5669_zps519b07ae.jpg.html)

[Mr. Man]

Glad to hear it's not to serious Joe Walsh. :cheer::cheer: Still think you need a big boy truck.:D;)