98 GT Running rough, smoking and with different exhaust temps!

[chunger]

Hi Guys,

Need some help here. I don't drive my 98 GT much (car only has 42k on it), and in fact had it parked in my garage for year, but a few months ago, I decided to drive it again. Car ran fine when parked. Charged the battery and went to start, and all it would do is crank. Realized fuel pump was dead, dropped tank and replaced. Guessed it's all the alcohol they add to gas today that locked up the old pump. Car ran great for 2 months.

Went to start the car a few times and got a weird slow crank, occasionally it would start and run real rough and sound like the timing was all retarded. Then, other times, it would fire right up like nothing was wrong and would run great. I caulked up the strange starts to a dying battery, as it's at least 4-5 years old.

Changed the oil last week (Mobil One), and went to start the car and it ran super rough and smoked at idle. Double checked everything under the hood, couldn't find anything wrong. Was sure car had a vibration at around 1500 rpm. Pulled plugs, most looked ok, except #8, oil fouled. Cleaned MAF, no change. Changed plugs (still had original plugs), to Autolite AP104s, still ran rough. Thinking my smoke was being caused by a sticking injector (hey - the fuel pump died due to additives in the gas, thought it might have gummed up the injectors too), swapped injectors with ones I pulled and cleaned from a '96 GT. No change, still ran rough. Pulled plugs again, most look fine, some light fouling/deposits on 5-7, could be from when I pulled the injectors and spilled fuel from the rail down the injector holes. Plugs #4 and #8 are black and oil fouled. In fact, #8 had oil dripping from the electrode. This set of plugs was in for less than a hour of runtime.

Swapped plugs out Motorcraft SP-432's. Car runs 'better' now, vibration seems to be mostly gone, BUT, car still has a definite miss, idle recovery is slow and dips to around 400-500 before settling. Car still smokes, just not as much, I'd call the smoke white. And, here's the funny part, the exhaust temps (at the outlet tip) are different, by 75-80 degrees! The right side is so hot, you can only hold your had at the tip for about 10 seconds before it's just too hot, the left side exhaust is lukewarm at best.

So, to recap, my symptoms are:
1. Miss, present at idle, and when driving.
2. Down on power
3. White smoke from exhaust, worse warm than when cold (I think)
4. Wildly different exhaust temps
5. Problems persist with plug changes.

I should also note that the car has NEVER given a check engine light throughout all this. One time, I unplugged the IAT sensor just to see if it would throw a code, it did and I cleared that.

HELP - I'm not sure what problem I'm chasing here. Any ideas?

Thanks!

 

[Three50won]

chunger...maybe your piston rings or the pistons themselves are cracked. That seems to be the only logical answer. Do a compression check and see. Or get a boroscope (probably didn't spell that right) and you can look right in and see whats going on. But I'd say you might have some internal engine damage.

 

[DavidEwers]

what does your oil look like? White smoke not grey usually means a bad head gasket, cracked block and or head. But the number eight plug being oil covered make me think you may have a bad oil ring on that cylinder.

I would run a leak down test asap

 

[trinity_gt]

I'd start by checking the ignition system: coils and wires to be specific.

A compression test might be in order as well...

 

[chunger]

chunger...maybe your piston rings or the pistons themselves are cracked. That seems to be the only logical answer. Do a compression check and see. Or get a boroscope (probably didn't spell that right) and you can look right in and see whats going on. But I'd say you might have some internal engine damage.

Sure, I can see the logic - BUT this is a car with only 42k on it! Compression check is a good idea, I've got a tester, dunno if it'll fit all the way down the plug hole on a mod motor. I'll try that today.

Can you rent borescopes? I think they're pretty expensive to buy, aren't they?

 

[chunger]

I'd start by checking the ignition system: coils and wires to be specific.

A compression test might be in order as well...

Ok, how? I put my timing light on each of the plug wires, all seem to be firing. Any way to test the 2 coil packs?

 

[chunger]

what does your oil look like? White smoke not grey usually means a bad head gasket, cracked block and or head. But the number eight plug being oil covered make me think you may have a bad oil ring on that cylinder.

I would run a leak down test asap

Can these testers be rented anywhere?

 

[DavidEwers]

Can these testers be rented anywhere?

I am not aware of anyplace that rents these out, try calling some race engine shops and ask them if they would rent one out to you.

 

[chunger]

Ok, had some more time to play around with it today and I think I found the source of my issues. Pulled all the plugs and did a compression check. All cylinders were 175-185, with most being right abouts 180. All except #8 that is. Cylinder #8 is dead, ZERO compression. Zero. Yikes.

Tried to pull the valve cover and I can't quite get it out, it's hitting on the clutch cable and/or throttle cables. Do these need to be removed to take the valve cover off?

Also, I can peek around the cover and sure enough, the follower for #8 is off and laying in the head. WTF? Is this a common thing on mod motors? I've never seen a engine just have the valvetrain fall apart like that.

Soooo, can this follow (I'm calling it a follower as it look kinda like a rocker arm, has a roller on it and it follows the cam to actuate the valve) - can I slip it back in? Do I need to loosen the cam hold downs to get enough room?

Thanks!

 

[Dan_Soprano]

Ok, had some more time to play around with it today and I think I found the source of my issues. Pulled all the plugs and did a compression check. All cylinders were 175-185, with most being right abouts 180. All except #8 that is. Cylinder #8 is dead, ZERO compression. Zero. Yikes.

Tried to pull the valve cover and I can't quite get it out, it's hitting on the clutch cable and/or throttle cables. Do these need to be removed to take the valve cover off?

Also, I can peek around the cover and sure enough, the follower for #8 is off and laying in the head. WTF? Is this a common thing on mod motors? I've never seen a engine just have the valvetrain fall apart like that.

Soooo, can this follow (I'm calling it a follower as it look kinda like a rocker arm, has a roller on it and it follows the cam to actuate the valve) - can I slip it back in? Do I need to loosen the cam hold downs to get enough room?

Thanks!

Valve stuck open?

 

[trinity_gt]

What you're referring to is sometimes called a "finger follower". It is held in place by the valve stem, the cam lobe and the lash adjuster ("lifter"). If you've got no compression and a follower out of place then I'd agree with Dan above: a valve is stuck open.

You can slide the followers back in, especially if the valve is open a bit (though it will just fall out if the valve is blocked from closing fully...)

Now, valves don't just stick. I mean, it's remotely possible gum or varnish on the valve stem might be causing some binding but it would have to be pretty gummed up. IMO, it's more likely something has gotten into the port and is physically stuck between the seat the valve face.

You'll have to get that valve cover off and do some more looking. Is the follower that's off on an intake or exhaust valve?

 

[chunger]

Got the valve cover off, had to remove both the throttle linkage and clutch cable, then the cover came right off.

Sure enough, the finger follower was laying in the head. As I sat there staring at it, I think I can recall exactly when it came out. I had just changed the oil and went to start the car, there was a strange sort of metallic 'ding-ding' sound, which at the time I couldn't place as I had never heard anything like it. That must have been the follower falling out of place.

It appears that the valvetrain is oiled via the lifter or lash cap. Is there also oil pressure on this? I'm thinking that when I changed the oil, it must have lost pressure and allowed the follower to slip out.

I'm thinking that if I apply air pressure via my compression checker, if a valve is stuck open, I should hear it, either out the exhaust or intake, right?

About slipping it back in... I can get it most of the way:

How do I get it that last little bit? I'm soooo tempted to loosed the cam girdle to gain a bit of room as slip it in - would this be a bad idea?

Thanks!

 

[Modular2v]

Got the valve cover off, had to remove both the throttle linkage and clutch cable, then the cover came right off.

Sure enough, the finger follower was laying in the head. As I sat there staring at it, I think I can recall exactly when it came out. I had just changed the oil and went to start the car, there was a strange sort of metallic 'ding-ding' sound, which at the time I couldn't place as I had never heard anything like it. That must have been the follower falling out of place.

It appears that the valvetrain is oiled via the lifter or lash cap. Is there also oil pressure on this? I'm thinking that when I changed the oil, it must have lost pressure and allowed the follower to slip out.

I'm thinking that if I apply air pressure via my compression checker, if a valve is stuck open, I should hear it, either out the exhaust or intake, right?

About slipping it back in... I can get it most of the way:

How do I get it that last little bit? I'm soooo tempted to loosed the cam girdle to gain a bit of room as slip it in - would this be a bad idea?

Thanks!

DO NOT LOOSEN THE CAM HOLDER! Take a pry bar and compress the valve spring a little so the rocker arm will pull up a little more allowing u to get the lash adjuster back in.

 

[trinity_gt]

Take a Philips ("star") head screwdriver and push down on the dimple/hole in the lifter plunger to try to compress it. Right now it's at full extension because there was no counter to engine oil pressure. If you do that you should be able to slip the follower back in.

I agree: Don't touch the cam cap bolts. Try compressing the lifter or the valve spring a bit if that fails.

And yes, forcing compressed air into the cylinder will tell you which valve is open. Looking at the pic and the valve involved I believe you're going to find it's the intake on that cylinder (someone correct me if I'm wrong...)

 

[DavidEwers]

If you have zero compression and you suspect a valve is stuck open you have a larger problem. If you have been running this car with a valve stuck open, it is more than likely that the valve has come into contact with the piston. You could have a whole in the piston now. Now is the time for that bore-scope.

 

[bhuff30]

Draining the oil or even loosing oil pressure while running will not cause the follower to pop loose. The follower popped off on its own... it WILL pop off again unless you fix the problem. Keep digging. Look at the valve springs to make sure they are fine. Could also be a sunken valve seat, bent valve, bad lifter, ect ect.

In my personal opinion (and experience), the worst thing you can do to a car is let it sit. The seals, bearings and other components get dry and the likely hood of problems increases.

Hi Guys,
... Realized fuel pump was dead, dropped tank and replaced. Guessed it's all the alcohol they add to gas today that locked up the old pump...

Sorry, but nope. Your car was designed to run on up to 10% ethanol and that is the maximum allowed in any state still. I have run MANY tanks of E85 (up to 90% ethanol) through my 97 GT without an issue. My original fuel pump lasted to 191k miles which is better than most. Other than changing the fuel filter once, for good measure, the rest of the system hasn't been touched, including injectors, seals and lines. Car has 196k miles now.

My 88 mustang was probably not designed by ford to run on the 10% ethanol gas, yet I have been running on E85 since 2005 and I haven't have any fuel system troubles with it.

 

[chunger]

Draining the oil or even loosing oil pressure while running will not cause the follower to pop loose. The follower popped off on its own... it WILL pop off again unless you fix the problem. Keep digging. Look at the valve springs to make sure they are fine. Could also be a sunken valve seat, bent valve, bad lifter, ect ect.

Bizarre, that's all I can say then. I think what is most perplexing about all this is that the car only has 42k on it. I bought it 5 years ago at 23k. And since I work from home, it spends most it's time sitting in the garage...

In my personal opinion (and experience), the worst thing you can do to a car is let it sit. The seals, bearings and other components get dry and the likely hood of problems increases.

Agreed. Sitting is never good for a car. But, still - having a rocker arm pop out while the car's sitting in the garage? Weird.

Sorry, but nope. Your car was designed to run on up to 10% ethanol and that is the maximum allowed in any state still. I have run MANY tanks of E85 (up to 90% ethanol) through my 97 GT without an issue. My original fuel pump lasted to 191k miles which is better than most. Other than changing the fuel filter once, for good measure, the rest of the system hasn't been touched, including injectors, seals and lines. Car has 196k miles now.

My 88 mustang was probably not designed by ford to run on the 10% ethanol gas, yet I have been running on E85 since 2005 and I haven't have any fuel system troubles with it.

Hmmmm, did not know that. Here in California, e85 is uncommon. I have only 'heard; on one station that sells it, never seen it myself.

Thanks for your thoughts!

 

[chunger]

Well, thought I'd update everyone with todays progress. Although the ending is as strange as the beginning...

I was able to get the follower back in place via 2 screwdrivers, one the upper side of the cam pushing down in it, and the handle on the other end on top of the spring. I don't have a leak down tester, so I fabbed up a pressure tester using the end of my compression tester. I turned the engine over to get both the lobes of #8 on the base circle:

(sorry about the photo, I rotated and cropped it on Photobucket, but it's still showing the original)

This was at least as close as I could get. I should have paid attention to the warnings to not keep my hand on the ratchet, while letting air into the cylinder. Of course, the engine spun over and slammed my arm into the radiator tank. Oh well, some lessons you have to learn over and over again. I now have a nice bruise on the inside of my left arm to remind to me pay attention...

Now, the bad news, I opened the valve and let air in and it all escaped! I couldn't pinpoint exactly where the air was going, it wasn't the exhaust, I don't think it was the intake, so that leaves the crankcase, right?

Anyways, I put everything back together and it fired right up. I could tell instantly that once again it was firing on all eight cylinders! Nice idle, no more smoke and back to even temps at the exhaust tips! Woo-hoo!

So, I took it for a drive. My heart sank through the floorboards as I took off down the street and it had a definite miss. Power was back, but still it had a miss. Thinking that this must mean a bent valve, I almost turned around at the end of my street. But, I said, F it, and kept driving. Somewhere between 1-2 miles, the miss cleared up. I kept driving - it now runs fine, just like it's supposed to.

I guess the miss could have been a bit of carbon on one of the valve seats? Dunno, but I'm happy, to say the least. It appears all my issues have been resolved and I consider myself very fortunate to have dodged bigger issues.

Thanks Stangnet! I couldn't have done it without all you awesome guys!

 

[mransr]

the miss may just have been the computer "re-learning" after the battery was disconnected...mine always takes a few miles and cycles before it's back to 100% after the battery is unhooked.

 

[DavidEwers]

if you think you have a carbon build up I would suggect you get some cleaner through the who system. Glad to hear that is running fine.