Disappearing coolant, shudder at idle-- different problems?

Swimupstream

New member
I'm not good at keeping short, hate leaving out details.
235k miles

Last September (about 8,000 miles ago) replaced the water pump. (and reservoir cap) All good.

PROBLEM 1: In February noticed the coolant was low. :noidea:
Topped it off, took a peak around, and started keeping an eye on it.
Coolant was dropping.
Did a really good burp on the system (twice). Still loosing coolant.
Absolutely zero sign of external leak. I have a bit of a valve gasket cover leak, but very minor, no dripping, just pooling on both rear corners. But I've been up under around through inside and out, week after week, and ZERO sign of leaking or aggregation. Completely dry besides those gasket corners.

I used a head gasket sealer, not a cheap one, directions to a T. After 2 weeks, still losing coolant. At the rate of I'd say 6-12oz per 1,000 miles? (Company did honor their guarantee and refund the money)

No white exhaust. Oil looks fine... changed in February (that's when I noticed it) and still now. [Of course I may not completely know what I'm looking for]

PROBLEM 2: About a month ago I started noticing a shuddering at idle. Idle seems low about 5500-6500. But it doesn't stall. Sure feels like it's about to, but it doesn't. When accelerating and coasting, everything is just fine. No bucking, no studdering or shuddering, smooth, no hesitation.

The wobble has been getting worse in the last week or two and I've gotta do something about it.


I have a bunch of theories, but This is about where my intelligence stops. I have no clue on the validity.
  • Head gasket leak getting much worse
  • Loss of compression (but wouldn't that affect it always?)
  • Unrelated misfire
  • Sensor issue of a million kinds

Ask me some questions and get me to figure some things out. Whether they are even related issues or not.


Outside of being annoying, I can deal with, but concerned to understand the issue to address it before I make it worse or cause another problem.


Thanks family!
 
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Do you have a waterfall sound behind the dash when starting the truck?

From reading your post, it sounds like it could be a possible head gasket leak.

Do you have any check engine lights on? If so, what code is it throwing?

I know you mentioned yours is an 05 but do you know the build date (month and year)? It is on the sticker inside the driver's door.
 
Sorry to say it's almost certainly head gaskets. Just did mine on my '04 2 weeks ago...

Mine had no misfire, but a loss of coolant and no external leaks. Easiest way to know for sure is to put a coolant funnel on the radiator and fill the funnel half way. Run the truck and burp the upper radiator hose and watch for bubbles. Mine had tons of tiny ones an occasionally a big one, that when popped smelled of exhaust. It would seal itself after running for 10 minutes or so.

Best of luck
 
If you do the coolant funnel, which is a good idea, add distilled water to the funnel. When it starts to change color, your thermostat has opened.

I used a funnel similar to this: Amazon.com: OEMTOOLS 87009 No-Spill Coolant Funnel Kit, Near Universal Fitment, Translucent, 15 Piece Set, Cooling System Funnel Allows Access To Hard-To-Reach Radiators: Automotive. It comes with a special rad cap with a little port for the funnel, so its a nice spill free system with a big area to see bubbles and color change

Also should be noted that this isn't normal coolant color. Its a smoothie of green some dumb shop mixed in with SLL Pink



Also I'd pull your plugs and take a look. Particularly 4 and 6 is where us v6's typically see the coolant leak into the cylinders occur.

Also check for leaky injectors. Some have seen this as a false positive for misfire from coolant leaking into cylinders while sitting, when its really excess fuel that leaked into the cylinder causing the misfires on startup. That doesn't solve your coolant loss problems, but in case the issues really are independent, its a potential culprit for startup misfire

I am afraid this does sound like HG though and that they are probably related. Hopefully you get it figured out without too much more headache
 
Same boat

I had the exact symptoms on my 2004. Eventually, I got a misfire going home one night and I decided not to drive her anymore until I got the Head Gaskets done. I didn't want to warp my heads beyond repair. I replaced mine at 170k. Hoping to get another 150k out of her lol
 
Have to say I agree with others, sounds like headgasket, had to have mine done 5 or 6 years ago on my '05. Started with a rough idle at start and would eventually relax, only seemed to be when engine was cold. Eventually it got worse, check engine lights came on and started to see white smoke out exhaust. If you have a check engine light on run the codes, if you have a misfire on 4 or 6 (like stated above) you most likely have your answer, headgasket. You could try swapping the ignition coils to see if the misfire changes location but if there is loss of coolant I doubt that a faulty ignition coil is the issue. As for the sealer not working I'm not surprised, everything I read about those seem to be hit and miss, depends where the leak is and really isn't a long term fix. If it is the headgasket get it fixed properly and you won't regret. I'm happy I spent the money and committed, has run great since and very happy to still have it around.
 
Thanks [MENTION=136431]metramm[/MENTION].

No waterfall sound.

Build date is mid-late-- April 05.

Have had check engine lights for years that don't resolve. O2 sensors which have been replaced, cam shaft position sensors, replaced. Soemtimes a misfire code.

(I bought the truck at 160k with the intention of restoring it... and spent the next several years chasing my tail just getting it "fixed." Now just want to make it live 2 more years 'til it's my turn for a new vehicle. Wish I could find a good enthusiast to take this one... lots of heart in it.)
 
Seriously, thanks gang. [MENTION=122919]rumfoord[/MENTION] [MENTION=479314]Nevek08[/MENTION] [MENTION=429038]y=mx+b[/MENTION] [MENTION=475044]Warwicke36[/MENTION]
Not just fast responses but valid, helpful, and intelligent. Your time is valuable and I appreciate using yours for the feedback.

I think the #1 thing is the reinforcement that I shouldn't imagine some 5-legged cat.... it probably is what it seems it is. Just appreciate that.

When I burp it I only notice early bubbles of the refill just trickling into the radiator, but then again the last several times I've definitely walked away and just let it run for the half hour, peaking out once in a while to be sure something didn't go awry.

I'll do the burp again and stick around, and give the injectors and coils steps a go on Monday-- just because I'm too stubborn to not try EVERYTHING at least twice to confirm it didn't work.... :frusty: :)

I'll let you know what I find.
 
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I had the exact symptoms on my 2004. Eventually, I got a misfire going home one night and I decided not to drive her anymore until I got the Head Gaskets done. I didn't want to warp my heads beyond repair. I replaced mine at 170k. Hoping to get another 150k out of her lol

[MENTION=479314]Nevek08[/MENTION], since you're local, where'd you go, how much did you pay and would you recommend them?

I'd love to learn it myself but it'd be at least a few days off and on for me and I don't know that I have the ability to have the vehicle down that long plus time investment anytime in the near window.
 
Seriously, thanks gang. [MENTION=122919]rumfoord[/MENTION] [MENTION=479314]Nevek08[/MENTION] [MENTION=429038]y=mx+b[/MENTION] [MENTION=475044]Warwicke36[/MENTION]
Not just fast responses but valid, helpful, and intelligent. Your time is valuable and I appreciate using yours for the feedback.

I think the #1 thing is the reinforcement that I shouldn't imagine some 5-legged cat.... it probably is what it seems it is. Just appreciate that.

When I burp it I only notice early bubbles, but then again the last several times I've definitely walked away and just let it run for the half hour, peaking out once in a while to be sure something didn't go awry.

I'll do the burp again and stick around, and give the injectors and coils steps a go on Monday-- just because I'm too stubborn to not try EVERYTHING at least twice to confirm it didn't work.... :frusty: :)

I'll let you know what I find.

I hung on to hope that I had some other issue for about 7-8 months. I was losing about 1-2 ounces of coolant every 500 miles or so. For what its worth I did a block test with color changing fluid and it passed. I ran the vehicle with the radiator cap off and never found bubbles or smelled exhaust. It wasn't til I bit the bullet and put a funnel on it and watched that I knew for sure. Even then if I didn't squeeze the upper hose as I tested I didn't see any bubbles. My point in all of this is it is very easy to convince yourself "Maybe it's ok and it's something else."

Just as important to mention...you should definitely verify that it IS your problem too! It would be a costly and heart breaking endeavor to think head gaskets only to find you happen to have a small external coolant leak and a bad ignition coil or worn out plugs.

Best of luck. Keep us psoted.
 
Trophy winner for pegging my productivity to a T!
"My point in all of this is it is very easy to convince yourself "Maybe it's ok and it's something else."
 
If you need advice on what to do if it is head gaskets let me know.

I replaced Head Gaskets (and various gaskets that come in the kit) ... Timing chains (my guides and tensioner were fine) ... Water pump ... P/S pump and lines (lines were a little crusty) ... Serpentine belt, tensioner and idlers ... Transmission Pan and dipstick tube (yes mine is the kind that has it and they were rusty (the top section has to come out to get the exhaust manifold out)

Also, I got freaked out reading alleged horror stories of people who milled their heads and then had issues. My heads were milled .008" (which is kind of a lot) and everything is fine.. I do recommend replacing timing chains for sure. $312 my cost from the dealer for the 3 chains.... but you MAY see a timing issue if your chains are stretched and you have to mill the heads...it would compound the issue of the stretched chains.

The job itself is about 22 hours not including extra for rust or additional work that needs doing. Plan on the machine shop needing a day or 2 to check and mill the heads.... You are looking at a week of down time minimum IMO. Even a great shop isn't likely getting this done in less than 4 or 5 days.

Anyways... these are all the things I went through in dealing with this mild headache.
 
If you need advice on what to do if it is head gaskets let me know.

I replaced Head Gaskets (and various gaskets that come in the kit) ... Timing chains (my guides and tensioner were fine) ... Water pump ... P/S pump and lines (lines were a little crusty) ... Serpentine belt, tensioner and idlers ... Transmission Pan and dipstick tube (yes mine is the kind that has it and they were rusty (the top section has to come out to get the exhaust manifold out)

Also, I got freaked out reading alleged horror stories of people who milled their heads and then had issues. My heads were milled .008" (which is kind of a lot) and everything is fine.. I do recommend replacing timing chains for sure. $312 my cost from the dealer for the 3 chains.... but you MAY see a timing issue if your chains are stretched and you have to mill the heads...it would compound the issue of the stretched chains.

The job itself is about 22 hours not including extra for rust or additional work that needs doing. Plan on the machine shop needing a day or 2 to check and mill the heads.... You are looking at a week of down time minimum IMO. Even a great shop isn't likely getting this done in less than 4 or 5 days.

Anyways... these are all the things I went through in dealing with this mild headache.

Wow, Warwicke, I had almost the exact same experience. I replaced pretty much the same stuff as you but I had just done the water pump, pulleys, belt, tensioner and ps pump a month before I found out my head gasket was leaking. And I went aftermarket on the timing components, (Cloyes brand) and replaced everything but the VVT units. I actually had one of my upper tensioners that had lost the plastic part that the chain rides on. I had the machine shop grind the valves, and put new valve seals on, and they milled mine .004. Also, my chain was so stretched it had the cams a whole tooth out of time, (retarded). It has more power now and a much smoother idle.
 
Hey Swim, I agree with the others; likely head gasket. On mine it passed a pressure test and a combustion gas test. In fact the only way I was able to verify it was to remove the #6 spark plug, pressurize the cooling system to 25 PSI, and look in the #6 cylinder with a borescope. I was able to see coolant come out from between the head and the block and run down the cylinder wall. About one drop every 45 seconds. Like Warwicke I ended up doing the timing components and having the head serviced and leveled. Due to parts delays it was down about a week and a half. I did all the labor myself except the machine work and ended up with about a grand in parts and machine work. About a month prior I had replaced the water pump, belt, belt tensioner, all pulleys, front crank seal, and power steering pump.... all of which had to come back off to do the heads, uggghhhh.
 
A little more diagnostic work as suggested may help you definitively answer if it’s the head gasket or not. I agree with pressurizing the coolant system. If it isn’t the head gasket but just a coolant leak, this may help you figure out where it is which would
Be a win as well. You can rent a tool from your local auto parts store and it doesn’t require any special tools.

A leak down test might be helpful, but only if you are having issues with the gasket sealing around the combustion chamber. That does require an air compressor though. I’d for sure start with the coolant pressure test first.

The combustion gas in coolant tester may be an option but I don’t have much luck with it in my hands
 
A little more diagnostic work as suggested may help you definitively answer if it’s the head gasket or not. I agree with pressurizing the coolant system. If it isn’t the head gasket but just a coolant leak, this may help you figure out where it is which would
Be a win as well. You can rent a tool from your local auto parts store and it doesn’t require any special tools.

A leak down test might be helpful, but only if you are having issues with the gasket sealing around the combustion chamber. That does require an air compressor though. I’d for sure start with the coolant pressure test first.

The combustion gas in coolant tester may be an option but I don’t have much luck with it in my hands

Me either. Mine was inconclusive at best. Supposed to turn yellow, just changed to a bluish-green color.
 
Well, everyone was virtually spot on.

End of story: When I get out tomorrow morning I'm picking up my truck from the mechanic.

Didn't get to do the work Monday... called in to work Sunday so Monday was way off. Ran to pick up a Craigslist paddleboard downtown.... About halfway down the interstate wasn't wanting to go faster than 50 without a bit of a punch of gas.... did it again... then a sudden tick-tick-tick-tick-tick and a burning odor. :tape2:

Played that game before, wasn't about to screw around to see what happened. Got it on the shoulder and idled it (yes I know) off the next exit.

Couldn't find anything immediate, but did notice it was wet on the front of the block.

Let it sit a bit to cool off in the rain. Oil level was on the lower side of full, color and consistency was good. Didn't work too hard at nailing down the source of wet, just no dangling hoses or blown stems/necks obvious. Tried a quick turnover of the engine and that did NOT sound good. Left it alone and flatbedded it.

That was evening. Left a msg for the mechanic. At 1130 the next morning he left me a message-- all done!

Misfire on #6, blew the plug out! (Says he's rarely seen it and he's been around, and a couple small ideas why.) Melted the coil. He pulled the coil, cleaned it out, re-tapped it (couldn't get the new one to seat), new coil and plug, topped it off-- voi la!!!!!!! Smooth idle. (clearly I did a pretty poor assessment under my frustration if I couldn't see that)

He ran a pressure test after me talking about the disappearing coolant... a couple of minor leaks at the main hose and at the water manifold that I disassembled and cleaned up last September when I replaced the water pump-- enough to be slow enough to leak and evap without dripping down or leaving obvious residue.

He's admits it's not 100% on the coolant leak right this second, but said he's seeing nothing else that indicates a head gasket at the moment or reason to dig deeper until I notice it continuing to happen.

Way out of my scope of practice and skill, even as simple as it would be to learn it all. Heck, the re-tapping and the pressure test alone were worth every penny-- $350 for the whole gig!

Guess God took that one out of my hands out of pity of me spinning my wheels... would have been another 2 months for me poking around and back and forth!

Keep an eye on it for a while and see what happens!

Thanks gang.
 
Well that's a hell of a win.

I would immediately retorque the other 5 Plugs... odds are whoever did the last set didn't torque em down properly.
 
Well that's a hell of a win.

I would immediately retorque the other 5 Plugs... odds are whoever did the last set didn't torque em down properly.

Hell yeah.

Good thought... I haven't touched the plugs (did #3 a few years ago) for 73k since I had the engine overhauled after I bought it... :withstupid:
 
Y'know, I never did post the final finding on the disappearing coolant.

Kept losing it after this and just couldn't find the wet spot or any drips. But nothing else said head gasket... Then I poured the rest of the gasket repair in and waited... and waited... and checked--- ah.. maaaaybe..... and checked... and checked again--- Voila!

The head gasket repair was just being coolant leak repair! (which would have been a boat ton cheaper!)

Shows you how good my observational skills are... Look at all the crap built up on the connection of the main coolant recirc hose!!!! Who in the heck would have missed that?! (Me) It's SCREAMING Leak is here!!!! Not to mention the drip line on the bottom of it.

You can also see clearly the dried coolant (white stains) on the S hose from the water manifold (I believe it's a recirc line?).

Tightened down the coolant hose and got a new spring clamp for the S-hose... and (even today, 5 months later), coolant level hasn't dropped a millimeter!


All that headache and anticipation and worry and calculating. But y'know what... I learned a lot, I was humbled for not paying closer attention to the minor stuff, and made some new friends. :)

Thanks gang, hope this helps someone!

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