Taurus Car Club of America : Ford Taurus Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter · #1 ·
It seems like every time these Tauruses have a problem, a misfire code is always involved. Here's my tale of woe:

2002 Taurus with the Vulcan 3.0. Just clicked over 80k on the odometer. Picked it up from a good friend who didn't feel like messing with it when the CEL came on. I believe it belonged to his mother who is now in an assisted care facility and no longer drives. This will be my son's first car and we got a good deal...I think.

First major repair was the water pump. The bearing was so noisy and worn, I'm surprised it wasn't leaking everywhere. Not a bad job. Changed the lower radiator hose, idler pulley, and serpentine belt while we there. The engine is super quiet now!

On to the CEL.... The scan tool showed P0301, P0302, and P0316, the typical misfire codes. We changed out the wires (number 2 almost turned to dust) and plugs. Motorcraft replacements for everything. The coil pack looked brand new (also Motorcraft) so we left it alone.

Cleared the codes, but P0301 keeps returning and the engine definitely has a miss on #1. I can pull the injector lead and there's no difference in the way the engine sounds. I have swapped plugs and wires with no change. I looked at #1 with a test plug and the spark looks good.

Checked the fuel pressure and it's running about 30-40 lbs. Injector 1 is delivering fuel as I used it to bleed down the fuel rail by applying 12v to it. Changed the fuel filter, but it didn't make any difference. Did a compression test over the weekend and #1 is the lowest of the 6 at 125 lbs. The rest run from 150-200.

I've checked for vacuum leaks, but found none. Disconnected the battery to allow the ECU to reset. Now the CEL doesn't come on, but the engine still has a miss, so I figure it's only a matter of time before the light comes back on. I also need to get the car registered and that will require a smog check. I'm pretty sure it won't pass and when it doesn't, I'm tempted to leave it with the shop to try and fix the problem. Our fleet mechanic said he had an '03 with a similar problem. He ran a can of clean out thru the intake and it seemed to fix the problem. We thought maybe the location of the PCV valve was causing #1's intake valve to get nastier than the rest. I guess we could try that, but I'm not sure what stuff to run thru it or where to inject it while it's running.

I'm open to more suggestions before dropping the car off at the mechanic and signing my life away.
 

·
Registered
Joined
·
1,365 Posts
The relative low compression and your thorough testing of fuel and spark make it look like a mechanical problem. I would perform a leak down test (a better chck of cylinder sealing than compression testing) and go from there. If his mother parked the car for long periods and didn't change the oil, it could be a sludge buildup causing ring or valve sealing problems.
 

·
Registered
Joined
·
39 Posts
^+1 on the coilpack. An easy way to check it to swap 1 and 4 plug wires (the two top wires) restart the car and pull the injector clips. If the problem moved to the other cylinder you have a bad coilpack. Thats how I figured mine was bad. Or you can make a cheapy tester out of an old plug wire and plug. I just grounded it and checked for spark. My #1 coil was bad. It checked ok with an ohmmeter but refused to fire.
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #5 ·
Finally had time to bolt the new Motorcraft coil pack on. No difference: number one is still misfiring. My leak down tester won't fit down in the deep plug well, so I'm gonna have to work on Plan B. I did stop by the mechanic/smog guy and he offered up some suggestions, including the leak down test. He also said to put a vacuum gauge on it and have a look, which I did.

I hooked up gauge to the large fitting on the back of the UIM near the PCV connection. Gauge shows a steady reading of about 20" with the engine warm and at idle. It drifts occasionally, but it's very slow and only a couple PSI in either direction.

I guess the next step is pull the heads and see what's going on. I'm am SO not looking forward to that kind of wrenching right now, having just put new head gaskets on my Montero. Unfortunately there's not much left than can cause a low reading on only one cylinder other than some mechanical problem with the base engine. Yuck.
 

·
Registered
Joined
·
10,566 Posts
Pulling Heads?

Finally had time to bolt the new Motorcraft coil pack on. No difference: number one is still misfiring. My leak down tester won't fit down in the deep plug well, so I'm gonna have to work on Plan B. I did stop by the mechanic/smog guy and he offered up some suggestions, including the leak down test. He also said to put a vacuum gauge on it and have a look, which I did.

I hooked up gauge to the large fitting on the back of the UIM near the PCV connection. Gauge shows a steady reading of about 20" with the engine warm and at idle. It drifts occasionally, but it's very slow and only a couple PSI in either direction.

I guess the next step is pull the heads and see what's going on. I'm am SO not looking forward to that kind of wrenching right now, having just put new head gaskets on my Montero. Unfortunately there's not much left than can cause a low reading on only one cylinder other than some mechanical problem with the base engine. Yuck.
Might consider shade tree mech method of compression check. Pull the wire on the fuel pump. Crank it and it will start for a few seconds and die. Now, You want to crank the engine with no start. Listen to the rhythm of the starter speed. If you hear a skip in the beat every 6th time, then you have a low cylinder. Much easier than a gage compression check. Of course this is just a process of elimination. No skip in the cranking and no reason to pull the heads unless it is leaking water.

-chart-
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #7 ·
I've pretty much come to grips with the fact that number one is low. The computer says so and the compression tester says so. My concern now is why and where. Does anyone know of any common valve train failures with the Vulcan engine that might cause compression issues? Head gasket failures? The oil didn't show any signs of goo when we changed it. The coolant was nasty, but didn't smell of exhaust. Only the one cylinder is low.

The engine just clicked over 80k so I wouldn't expect anything serious, but of course, I have no previous history on how the car was maintained. The car is worth putting some money into it, but I want to make sure I don't put the money in the wrong place.

You guys have been great. Thanks for your ideas.

-Jim
 

·
Registered
Joined
·
1,365 Posts
Well you could pull the back valve cover and look at the rocker arm. It's possible a lifter collapsed and allowed a pushrod to fall off-center and jam a valve open.
 

·
Premium Member
Joined
·
14,356 Posts
What does the plug on cyl 1 look like? Pull that BEFORE going deeper.
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #10 ·
All the plugs look great, even the old Autolites that came with the car. They were worn, but the color was fine on all of them.

We'll start with the back valve cover and see what happens. Stay tuned!!
 

·
Registered
Joined
·
1,047 Posts
Have you had the charging system tested ? I found the attached TSB and it sounds like it COULD be the issue if you have a low / weak battery.
 

Attachments

·
Registered
Joined
·
3,377 Posts
Have you had the charging system tested ? I found the attached TSB and it sounds like it COULD be the issue if you have a low / weak battery.
i would do this before anything else. also check the ground locations and connections. how does the car crank when cold and hot? this wont fix the compression problem but might keep you from a rebuild for awhile
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #13 ·
The car fires right up, cold or hot, but it is definitely missing on cylinder 1. If I pull the injector connector off or the plug wire off, there's no difference in the way the engine runs. Battery seems to hold a charge. It starts after sitting a few days.

The TSB is a bit confusing as it doesn't say whether it the older firmware is causing the miss or just turns on the CEL with a miss fire code. Not real keen on visiting the local Ford dealer.

I'm tempted to pay the $35 for the Carfax report and see what's been done previously. Anybody had any luck with that product?

-Jim
 

·
Registered
Joined
·
1,047 Posts
My car fired right up and carried a charge too, but the batterys ampreage output was not enough and it caused wierd things to happen. Make sure to have the battery tested as a precaution.
 

·
Registered
Joined
·
1,365 Posts
My car fired right up and carried a charge too, but the batterys ampreage output was not enough and it caused wierd things to happen. Make sure to have the battery tested as a precaution.
He has had no problem with charging. He's already confirmed that the car is misfiring, it isn't a PCM calibration problem. That TSB has nothing to do with his issue.
 

·
Registered
Joined
·
1,047 Posts
How so ? BOTH DTC's are there listed in the TSB and he HASN'T checked his battery. It's like I said my battery was charging but it didn't have the amperage causing misfires and odd things to happen in the car.

Why complicate it ? one of the first things to check is the battery, especially in the Taurus.

It was a suggestion so take it or leave it, The ECU may not need a program but the battery should be checked.
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #17 ·
I'll have the battery checked out while the car is down for the count. I suspect the problem is in the base engine this time, however, not the electronics.

I was over at my local machine shop this week for another purpose and happened to mention the Taurus issue. When I told him which engine it had in it, he told me he pretty knew exactly what was wrong with it: valve seat recession. He said a number of years back, the local Ford dealer was keeping his bank account fat with cylinder head repairs. Which cylinder head? The Vulcan 3.0 V6, of course. He said Ford did not do a thorough job of heat treating the seats and if you used the cheaper blends of gasoline (and who doesn't?), the exhaust valves would start hammering themselves into the head.

Interestingly enough, he said the Ford dealer would only pull the affected head and only have his shop repair the bad seat. Another 10k miles down the road, you could probably expect to have the same problem and with any luck on the dealer's end, it'd no longer be a warranty repair. Bastards.

There is a TSB out there that reflects this exact problem on Ranger pickups with the Vulcan 3.0 engine. I don't see why the Taurus wouldn't be any different. Will find out this weekend as head removal is on the schedule. I'll have pictures as we go.

-Jim
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #18 ·
Quick update:

Got the heads pulled off over the weekend. The left head(front) was cherry. Combustion chambers were all nice and clean. The right head, however, has problems, but that's what the compression test was telling me. Cylinder 1 has a nice visible crack between the intake and exhaust valves. It extends all the way into the water jacket as there is evidence of coolant leaking. Cylinder 2 also has a nice crack coming off the exhaust valve and into the casting. There is evidence of coolant there, also, but apparently not enough leakage to generate any steam out the exhaust.

I'm gonna make an assumption what caused some of this. The car has a very new degas tank in it and evidence of rusty water underneath it. I'm gonna guess the tank cracked, the car overheated, and damaged the right head. The head bolts on that side required different amounts of torque to break them loose while the left side all seemed to take about the same amount of oomph to loosen them.

My local machine shop has a source for heads so I'm waiting to hear back from him. All in all, I've been impressed how relatively easy this engine has been to work on. Everything has unloosened & unbolted like it's supposed to. The only gotcha was the EGR differential pressure sensor. Both the plastic **** broke off. I'm considering changing out the camshaft synchro while I'm here as it is now super easy to get to.

One final happy note: the engine is very clean inside. Valve covers and lifter valley have no sludge build up at all. Looks like the p.o. kept the oil changed, if nothing else.

I'll have more updates when the motor is back together.
 
1 - 18 of 18 Posts
Top