Engine/Tranny/Driveline issues??

B

Blute

New member
So, I have a few problems going on, and I'm not sure if they are related, but thought I would post them up and see if anyone has ideas:

1) A few weeks ago, I was just cruising along, around 45-50 mph and around 1500 rpm, and then some weird shaking/vibrating started to happen, kind of like driving over some rumble strips. Let off the gas and it went away. It didn't feel like it was engine-related, just something else shaking. It does not feel like the front end or suspension, either. Pulled over and looked under the rig, and it looked fine. Started driving and it did not happen again.

2) I then started to drive up the canyon, and as I was accelerating up a hill at higher rpms (but slower speed, maybe around 30 or so), the engine felt it was sputtering and losing power. I let off the gas and it went away. I then turned around and headed home. When I got nearer my home, I found a hill and drove up it, accelerating hard again, and indeed the sputtering happened again. However, I never did notice the problem similar to #1 again.

So...a few days later, I replaced all the tranny fluid, and flushed it out good, and it seemed to run better and those symptoms disappeared for awhile. As party of the tranny fluid change, I also dropped the pan and removed and cleaned the filter. However, the symptoms are now back again. My son was driving it the other day, and accelerating up a hill, and he said it sputtered and lost power again (symptom #2), and the CEL even came on for a few seconds but went away. Today while driving it, I experienced symptom #1 again, with it shaking as I was just cruising along around 45 mph and 1500 rpm - and it went away when I let off the gas.

Some additional info - a few months ago, I noticed that the coolant was disappearing out of the overflow tank, but no visible leaks or drips anywhere. I would top it off every few weeks, but it was running fine. I eventually replaced the radiator cap, and that seemed like it has slowed the "leak", but coolant is still disappearing slowly. There is no sign of white smoke from the exhaust as far as I can tell, so I'm not sure if there is a head gasket problem or not. It's been several months before I last changed the oil, but I don't remember really looking close at the used oil or noticing anything weird with it. Also, when I changed the tranny fluid recently, I did not see anything that looked like the "pink milkshake" problem with coolant getting into the tranny fluid.

My '98 Runner has about 202,000 miles on it now. The radiator was replaced around 125-150k (can't remember the mileage exactly) when the wife had a fender bender. I change the oil every 5k and the oil in the diffs/transfer case every 30k. I also grease the driveshaft and u-joints every 30k. I have also cleaned the MAF and the TB recently.

Any ideas where to start? I may take it to a local mechanic to have a look, but wanted to see what all the good folks here might say first. Thanks!
 
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check the codes there might be a pending code. I am leaning toiwards a misfire. if the truck is bucking under load. could be simple plugs wires coils or complicated like injectors.
 
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Alright, borrowed a friend's code reader, and pulled the following code:

"PO303 Cylinder 3 Misfire Detected"

So what would be the next best strategy? Replace the plug/coil/wires, or try to diagnose something else??

I last replaced the plugs at 185k, and it has about 202k on it now. I used OEM plugs.
 
Blute said:
Alright, borrowed a friend's code reader, and pulled the following code:

"PO303 Cylinder 3 Misfire Detected"

So what would be the next best strategy? Replace the plug/coil/wires, or try to diagnose something else??

I last replaced the plugs at 185k, and it has about 202k on it now. I used OEM plugs.
Click to expand...

I think it could be the injector but swap the #3 coil with 1 or 4 and see if the code jumps to 1 or 4. If it doesn't then it's the #3 injector. Injector replacement pretty easy. A little work that's all.
 
You can also test the coil the two pins that connect to the wire terminal should be 0.67 - 1.05 ohms when cold or 0.85- 1.23 ohms when hot. But the coil swap would be a good indicator.
 
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spartacus said:
I think it could be the injector but swap the #3 coil with 1 or 4 and see if the code jumps to 1 or 4. If it doesn't then it's the #3 injector. Injector replacement pretty easy. A little work that's all.
Click to expand...

That's a good idea to swap coils. Do you mean swap with #1 or #5 (not #4)? Is the diagram on this page correct?
https://www.yotatech.com/how-tos/a/...2-how-to-replace-spark-plugs-and-wires-415119

Should I go ahead and replace the wires and/or plug(s)? I don't think the wires have ever been replaced...
 
Before anything else, I suggest you replace the spark plug (if not all of the spark plugs). Get OEM part number 90919-01192, it’ll cost you ~$3 and take less than 10 mins to change out the plug.

About 5 months ago I was chasing down a misfire problem in cylinder 3, and ruled out the plug because I pulled the plug and it looked good, and because I replaced all my plugs a year earlier. I swapped coil packs (didn’t work), got my fuel injectors services (didn’t work), checked compression (185 psi). I was puzzled. I finally decided to swap spark plugs with cylinder 1 and the misfire moved to cylinder 1. I spent about 3 weeks and ~$160 in a fuel injector service I didn’t really need and the problem ended up being a little $3 plug. It’s been running perfect ever since.
 
I'll be the pessimist.

You say you are loosing coolant but cannot see any leaks/drips anywhere. You also have a misfire code on #3 and a loss of power/sputtering.

It is possible that you have a bad head gasket. It is also possible that your HG is completely fine and your coolant loss is from something else like a leaky water pump (coolant burns off on the block before it gets to the ground if its a slow leak).

A leak down test would rule out or confirm a bad HG.

I only say this because I recently blew a HG (cylinder #3 misfire) and was mysteriously loosing coolant. I did a bunch of tests (dye test, inspected the cylinder etc) and the only test that was reliable was the leak down test. Once I pressurized the cylinder, I had air bubbles coming out of my radiator.

Plugs/wires are relatively cheap so you can certainly throw parts at it and it may fix it. It's entirely possible that it's something simple.

What would concern me is the mysterious coolant loss that you cannot find. You can remove the TB cover and using a mirror/flashlight and see if the WP is leaking. I also had a coolant leak awhile back from the two heater hoses on the back of the engine by the firewall. It would drip on the exhaust manifold and burn off so it would never leave any spots on the ground.

If you do a thorough search (free) and cannot find any coolant leaking anywhere on the exterior of the engine, I would be doing a leak down test....

Good luck either way
 
Thanks for all the tips. I think I will start with the following:

-Replace the spark plug wires (already ordered the NGK wires from Amazon).
-Replace the plug in cylinder #3 (already got some NGK plugs from Advance Auto - same as stock. I bought enough plugs to change all of them, although I'm not sure if that will be needed.)
-Move the coil to a different cylinder and see if I get another code.

I may also do the leakdown test while I have everything open. Haven't done this before myself, but after reading up on it, it doesn't seem very difficult. Question - if I do the test, should I test every cylinder, or only the problem one (#3)?
 
I would at least test all of the cylinders on that side (1,3,5). Make sure you read the directions on the kit, it's pretty straightforward.

Youtube has lots of videos showing you how to do it also.

If you have the time, or you are planning on changing out all of the plugs, you might as well do the other side too. It doesn't take long at all.

PS. This is the leak down test kit I bought, it's pretty nice. https://www.amazon.com/OTC-5609-Cyl...pID=51xtBQ2m0ZL&preST=_SY300_QL70_&dpSrc=srch
 
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Update:

I ended up replacing the plugs and wires a few weeks ago, and it has been running ok since - no more bucking, losing power, or anything like that. When I removed the plugs, I did find that plug #3 was a little harder to remove from the cylinder (difficult to turn with the ratchet), and it had a little bit more corrosion on it when compared to the other plugs. I also reset the CEL codes and it hasn't thrown any codes since.

Although it has been running ok, I did see a fair amount of white smoke from the exhaust one morning, but it hasn't happened since. My guess is I might have a head gasket leak, and it's leaking into the #3 cylinder. I think my next step will be to do a leak-down test on that cylinder and see what happens.
 
Blute said:
Update:

I ended up replacing the plugs and wires a few weeks ago, and it has been running ok since - no more bucking, losing power, or anything like that. When I removed the plugs, I did find that plug #3 was a little harder to remove from the cylinder (difficult to turn with the ratchet), and it had a little bit more corrosion on it when compared to the other plugs. I also reset the CEL codes and it hasn't thrown any codes since.

Although it has been running ok, I did see a fair amount of white smoke from the exhaust one morning, but it hasn't happened since. My guess is I might have a head gasket leak, and it's leaking into the #3 cylinder. I think my next step will be to do a leak-down test on that cylinder and see what happens.
Click to expand...

Just to throw my two cents in here, it might have just been a bad plug or ignition. I had identical symptoms to you in my 96 Avalon a few years ago. Turned out that some packrats had chewed through 2 of the spark plug cables and I was essentially running on 4 cylinders. Got it fixed and never had a similar issue again.
 
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