At a loss | Need help

[anormalflame]

All of my issues started with a misfire on cylinder 6 on the way to a dealership oil change. CEL came on en route.

I had never changed the plugs or wires on this truck so I started with that. I found oil in the plug tube on cylinder 1. I siphoned it out knowing soon I'd need to replace the seals along with my leaky valve cover gasket.

The misfire went away and popped up later on as p0301. I swapped coils around to see if the misfire moved. It did. Misfire is now p0302. Replaced the coil. No CEL or misfires for a while... But then misfires return and later escalated to p0300, p0301, and p0306. The truck idled rough. I removed and cleaned the throttle body, the IAC, and the MAF. I noticed one of the MAF's wires inside was somehow broken. Swapped it out. I changed the fuel filter as it had never been done and I was just keeping busy while trying to diagnose this.

Unfortunately the one mechanic in my family, my right hand man, my uncle, passed away two weeks ago before I changed my fuel filter as we were diagnosing over the phone long distance.

Around the time of replacing the fuel filter, I noticed white smoke out the tail pipe. OH NO! Began to research the issue. Of course, that led me to head gasket symptoms 101. There's no sweet smell. There's been no clear indication of coolant loss from the tank. Tonight I did a a block test and the blue test liquid didn't turn yellow. It barely changed from blue. uhhh

Work done:
Changed plugs & wires (found oil in cylinder 1 plug tube - siphoned out)
Cleaned Throttle Body
Cleaned IAC
Replaced MAF
Replaced Intake hose that was patched up by previous owner
Replaced Fuel Filter
Replaced PCV valve
Seafoam fuel additive (one full tank ago)

I'm still seeing a lot of white smoke that eventually goes away after driving a while. My check engine light doesn't come on anymore, but misfires sometimes still pop up under pending codes. Still seeing p0300, p0301, p0306. All of this and the truck rides fine. Throughout all of this the misfire indications are always p0300, p0301, and p0306. I'm aware I'll need to do a compression test and leak down test to really find out about the possibility of a coolant leak internally in the engine.

Are there any possibilities it's something else I've overlooked?

Pardon my lack of mechanical knowledge. I'm taking shots in the dark as my ace passed on to the big garage in the sky. I'm somewhat of an early DIYer (brake jobs, cv Axel swaps, drain and fill, somewhat small stuff, etc) Any insight would be appreciated.

 

[WeAreSLO]

This sounds exactly the random misfire issues that have been plaguing me as well. The misfire/check-engine lights come on only when I drive for over an hour or two - nothing on my 20 minute drive to work. I did a compression test the other day and 4 of the 6 cylinders came in at 185 psi, the 2 center cylinders measured an acceptable 170. Previously I've replaced the spark plugs/wires, cleaned MAF and never had an issue. The misfire codes only pop-up on long drives which leads me to think it might be the fuel injectors. It might be one of your injectors as well? There are a lot of misfire threads on this forum and one of the users discovered his misfire was caused by a cracked head, hopefully that's not the case for us. I don't get any overheating so again, leads me to think I need to start evaluating my fuel injectors and seeing if there's a short when one or more of them gets hot.

Funnily enough I did a 6 hour drive last week and the check engine light/misfire didn't occur like it has the last few times I've gone on long drives...very mysterious.

 

[LittleCaesar]

You need to perform a leak down test to rule out 100% that it is a bad HG, though not losing coolant is a good sign. Block tests aren’t always conclusive.

I’d start with this before proceeding with anything else.

 

[ElZilcho]

Slow down with all the "repairs". It'll make it difficult to figure out where the original problem ends and all the "fixes" begin. You started off on the right path. It's not uncommon for several coils to go at or near the same time. If the misfire stays consistent to cylinders 1 and 6 swap coils again, see if it moves and replace as necessary. If the coils aren't the problem I would examine the spark plugs. A leaky injector, vacuum leak, or crack in the air intake (post MAF) are all pretty likely culprits. The plugs will tell you if a cylinder is routinely running rich or lean.

Looks like Birmingham has been getting down to the thirties at night. My guess is the white smoke (especially if it goes away after the motor warms up) is condensation. Absent any other evidence of a head-gasket issue (i.e. low coolant or oil that looks like a chocolate shake) I wouldn't worry about a leak down. The oil in C1 plug tube, the misfire, and the smoke are certainly indicative of a head-gasket, but don't get caught up hunting zebras.

If the misfires are consistent to cylinders 1 and 6 start there and work out. Coil, plug, wire, etc. IAC, MAF, Throttle body would effect all cylinders equally. Last, don't take any of your previous repairs for granted. I can't tell you the number of times I've been plagued by a vague and intermittent problem, absolutely sure I had just fixed it, only to find out I had left something loose, mis-wired something, didn't get a connector together properly.

Be meticulous and dogged.

Sorry to hear about your uncle, but good luck on your truck.
[MENTION=106468]WeAreSLO[/MENTION] coils get a bit fussy when they are hot. Not saying that's your issue, but I wouldn't rule it out.

 

[anormalflame]

You need to perform a leak down test to rule out 100% that it is a bad HG, though not losing coolant is a good sign. Block tests aren’t always conclusive.

I’d start with this before proceeding with anything else.

Yeah that's what I thought. I'll have to pick up a cheap test kit at harbor freight and give it a go. Let's say the leak down test shows no indication of a blown HG. Any thoughts to what else it could be? Just curious if these are symptoms to another problem as well

 

[HiLife]

You can buy a compression tester at HF and keep it. Or you can rent one for free with a deposit.
27138 - Autozone
67062 -Orielly Auto Parts
776-8080 - NAPA - Not napa locations rent tools.

Condolences about your uncles passing. I know how it feels like. It hurts when you have someone you can really talk to is no longer there to talk about stuff. Keep you head up man.

 

[anormalflame]

Slow down with all the "repairs". It'll make it difficult to figure out where the original problem ends and all the "fixes" begin. You started off on the right path. It's not uncommon for several coils to go at or near the same time. If the misfire stays consistent to cylinders 1 and 6 swap coils again, see if it moves and replace as necessary. If the coils aren't the problem I would examine the spark plugs. A leaky injector, vacuum leak, or crack in the air intake (post MAF) are all pretty likely culprits. The plugs will tell you if a cylinder is routinely running rich or lean.

Looks like Birmingham has been getting down to the thirties at night. My guess is the white smoke (especially if it goes away after the motor warms up) is condensation. Absent any other evidence of a head-gasket issue (i.e. low coolant or oil that looks like a chocolate shake) I wouldn't worry about a leak down. The oil in C1 plug tube, the misfire, and the smoke are certainly indicative of a head-gasket, but don't get caught up hunting zebras.

If the misfires are consistent to cylinders 1 and 6 start there and work out. Coil, plug, wire, etc. IAC, MAF, Throttle body would effect all cylinders equally. Last, don't take any of your previous repairs for granted. I can't tell you the number of times I've been plagued by a vague and intermittent problem, absolutely sure I had just fixed it, only to find out I had left something loose, mis-wired something, didn't get a connector together properly.

Be meticulous and dogged.

Sorry to hear about your uncle, but good luck on your truck.

[MENTION=106468]WeAreSLO[/MENTION] coils get a bit fussy when they are hot. Not saying that's your issue, but I wouldn't rule it out.

Thanks for the reminder to slow it down. At one point I did have a code for running lean but it went away after removing the wires and plugs and putting them back in. For future reference, how are the plugs an indicator?

Also, the white smoke appears to be much more than condensation. It always returns and will continue to smoke after the truck is warmed up.

The misfires are certainly consistent with 1 & 6. I replaced the coil on 1 after I moved them around the last time and it jumped to 2. Code went away, but they come back as pending codes ever so often.

I replaced the intake hose due to a botch job the last owner had done to patch up what appeared to be a hole or crack.

Thank you

 

[HiLife]

How to read plugs.

 

[gamefreakgc]

Thanks for the reminder to slow it down. At one point I did have a code for running lean but it went away after removing the wires and plugs and putting them back in. For future reference, how are the plugs an indicator?

Also, the white smoke appears to be much more than condensation. It always returns and will continue to smoke after the truck is warmed up.

The misfires are certainly consistent with 1 & 6. I replaced the coil on 1 after I moved them around the last time and it jumped to 2. Code went away, but they come back as pending codes ever so often.

I replaced the intake hose due to a botch job the last owner had done to patch up what appeared to be a hole or crack.

Thank you

Does it ever smoke when the engine is hot and parked for a few minutes? I hope you are not insulted by us asking about the smoke/steam, but these 4Runners are known to put on quite a steam show in cold weather and many mistake it as coolant burning. If it really is coolant, you will smell it.

I agree on the leak down test but to do it you need an air compressor, just a heads up. Not everyone has one in the garage. Compression test is more to gauge the health of the pistons and valves as it can hold compression but still have a small leak or crack in the head.

By the way, have you checked your spark plugs? You might just need new plugs.

 

[anormalflame]

Does it ever smoke when the engine is hot and parked for a few minutes? I hope you are not insulted by us asking about the smoke/steam, but these 4Runners are known to put on quite a steam show in cold weather and many mistake it as coolant burning. If it really is coolant, you will smell it.

I agree on the leak down test but to do it you need an air compressor, just a heads up. Not everyone has one in the garage. Compression test is more to gauge the health of the pistons and valves as it can hold compression but still have a small leak or crack in the head.

By the way, have you checked your spark plugs? You might just need new plugs.

It smokes up on a warm day or a cold day. Doesn't matter which, it still smokes. Our temps have varied from 65 - 35 the past week. There is an odor, but it doesn't seem "sweet" to me. It seems to smoke slightly less now though and it's colder out.

In a few weeks I'm flying to Houston to gather my uncles tools, guitars, and other stuff. I'll have an air compressor then.

Changing the spark plugs / wires was my first step.

 

[anormalflame]

How to read plugs.

Thank you for this. They appear to be the same as when I put them in over a month ago, not wet or dry or any of the other symptoms, but this has great info.

 

[anormalflame]

You can buy a compression tester at HF and keep it. Or you can rent one for free with a deposit.
27138 - Autozone
67062 -Orielly Auto Parts
776-8080 - NAPA - Not napa locations rent tools.

Condolences about your uncles passing. I know how it feels like. It hurts when you have someone you can really talk to is no longer there to talk about stuff. Keep you head up man.

I must have missed this post. Thank for the info man. Yep he was my dude. The only way I know anything about this stuff is because of him. I was his wrench getter growing up. I paid attention and learned a lot. Keeping it up the best I can. Thank again

 

[ElZilcho]

How to read plugs.

This. The article is missing a couple of things though. Plugs in a properly running cylinder will be charred a goldish/brownish. A lean cylinder will be white and flaky. A rich cylinder is darker/blackish. A google image search and the terms "reading spark plugs" will give you an abundance of info. It will give you an inkling as to what kind of misfire you're having. Since you have new plugs it will make it easier to tell if one cylinder is running differently than the others, but without being able to look at the old plugs and reference which cylinder they came out of your missing a bit of a baseline.

When the problem began you may have had weak coils on cylinders 1,2, and 6. Swapping 1 and 2 proved that coil 1 was bad but doesn't rule out coil 2 being weak. Move them again and see if it changes. It's free (except for the time) and even if it doesn't change anything you'll have positively eliminated the coils and by reading the plugs you'll have some clue as to what's causing the misfire.

The lean code could have been the original faulty intake but again, you've done a lot of work now and it makes it difficult to prove causality. Start over and be methodical.

Good luck and remember this is all internet advice... it's worth exactly what you paid for it.:wave:

 

[LittleCaesar]

Yeah that's what I thought. I'll have to pick up a cheap test kit at harbor freight and give it a go. Let's say the leak down test shows no indication of a blown HG. Any thoughts to what else it could be? Just curious if these are symptoms to another problem as well

That is hard to say. I would a vigilant eye on the level of the coolant as well as try and get a sniff of the exhaust and see if it smells sweet. But white smoke that isn’t condensation usually points to a coolant leak somewhere.

Looking at the plugs also can say a lot. If one looks cleaner, or a different color, any anomaly from the rest, you may be able to pinpoint the source of the problem.

 

[thegipper]

You need to perform a leak down test to rule out 100% that it is a bad HG, though not losing coolant is a good sign. Block tests aren’t always conclusive.

I’d start with this before proceeding with anything else.

^This is exactly what you need to do.

Those dye tests are essentially worthless. By the time enough combustion gases are in the coolant to change the dye color, it should be blatantly obvious you have a blown HG.

I had a blown HG (#3 cylinder) and the dye didn't even remotely change color.

I then did a leak down test and once I pressurized the #3 cylinder, bubbles came out of the radiator neck. That is proof positive that my HG was bad.

A leak down test also tells you if there are problems with the valves, rings and so on.

Good luck

 

[Bad Luck]

Just a little more info that I don't think anyone touched on yet:
When doing a leak down test you need to have that cylinder at top dead center (all the way up on a compression stroke). Keep in mind that pistons come up twice per combustion cycle.
Air coming through coolant is likely a blown head gasket.
Air coming through oil fill is likely piston rings. (Will also show up as low compression.)
Air coming through throttle body/air intake tubing is likely intake valves improperly seating (or bent).
Air coming through exhaust is likely exhaust valves improperly seated (or bent.)

Good luck!