[Dustnailer]

Hey, I am new here and this is my first post. I have an 07 Colorado with the 2.9 - 4 cyl. 198,000 miles, 2WD automatic. I am going crazy here trying to figure this problem out. There is tan sludge all over the dipstick to the point that I can't check the oil and just recently I found about a 1/2 pint of water in the resonator box! I changed the oil and filter 2X made sure the PCV openings are clear, checked the compression, (It is good) and even had Blackstone labs run 2 tests on the oil in which they did not find any coolant or water! It seems to be worse since the weather got cold. I just bought the truck last July and the seller told me about the tan sludge in which he could not figure out. Anybody have experience with this or any ideas? I sure would appreciate some feedback and thanks in advance!

 

[Dragon08]

So you are not losing any coolant? Obviously the first thought is a bad head gasket, leaking coolant into the oil. But your tests indicate that is not the case. You verified that there is no oil in the coolant? Any gunk on the oil cap or radiator cap?

A search shows that several others have had this occur as well. But I didn't notice any actual resolution to make it stop. Just to keep your oil and cap clean. Does not seem to be a catastrophic event, but you like to know whats going on. It seems some trucks gather more water than others.......

HAve you checked the intake side of the PCV as well for proper flow?

Water in the resonator? Is it possible you have a leak or bad air filter that is allowing water into the air intake system. It would leak down the PCV tube from the resonator from there.

Is the airbox and ducting stock? Any water in the airbox? Is the water clean, or oily?

What about a leak where the dipstick enters the pan? Or other seal leak in the southern hemisphere of the engine. Though you would think you would blow oil out too. Just spitballing on that one.

When you drained the oil, was it milky? Did you let it settle to see if the water separated, like in a glass jar or something?

The water in the resonator is the big thing for me. Which end did it come from?

If you dont see signs of wanter in the oil, it could be just enough to be trapped in the dipstick tube somehow, and just spoiling your readings. but how is it getting in there? Thats your question obviously.

 

[Dustnailer]

So you are not losing any coolant? Obviously the first thought is a bad head gasket, leaking coolant into the oil. But your tests indicate that is not the case. You verified that there is no oil in the coolant? Any gunk on the oil cap or radiator cap?
Hey Dragon thanks for the good input. No coolant loss and yes milk in the oil cap.

A search shows that several others have had this occur as well. But I didn't notice any actual resolution to make it stop. Just to keep your oil and cap clean. Does not seem to be a catastrophic event, but you like to know whats going on. It seems some trucks gather more water than others.......
Yes this isn't that bad but it would be nice to know how much oil is in the pan.

HAve you checked the intake side of the PCV as well for proper flow?
I made sure both openings are clear and replaced the Left (Rear) PCV hose and it seems have water blowing up into the resonator box.

Water in the resonator? Is it possible you have a leak or bad air filter that is allowing water into the air intake system. It would leak down the PCV tube from the resonator from there.

Is the airbox and ducting stock? Any water in the airbox? Is the water clean, or oily?
No water in the airbox and everything under the hood is stock.

What about a leak where the dipstick enters the pan? Or other seal leak in the southern hemisphere of the engine. Though you would think you would blow oil out too. Just spitballing on that one.
Dipstick tube is lose but not leaking

When you drained the oil, was it milky? Did you let it settle to see if the water separated, like in a glass jar or something?
No milky looking oil and only found several water droplets. I had the oil tested twice and they did not find any water.

The water in the resonator is the big thing for me. Which end did it come from?
The water was all through the res box and mostly in the front. I thought about it coming in through a seam but I haven't hit any puddles, ever.

If you dont see signs of wanter in the oil, it could be just enough to be trapped in the dipstick tube somehow, and just spoiling your readings. but how is it getting in there? Thats your question obviously.

 

[Kenzen]

How's your operating temperature? Does the engine get hot enough to steam off the moisture in the engine?

 

[Dustnailer]

How's your operating temperature? Does the engine get hot enough to steam off the moisture in the engine?

Good suggestion, thanks for the response! I thought of that and the previous owner installed a new 195 thermo. Chev's temp gauges seem hard to read and the needle gets just above the halfway mark. I recently changed the Valve timing sensor which made it run a tad cooler but had this problem before the sensor was changed. Do you have any idea how to read the temp gauges?

 

[Dustnailer]

So you are not losing any coolant? Obviously the first thought is a bad head gasket, leaking coolant into the oil. But your tests indicate that is not the case. You verified that there is no oil in the coolant? Any gunk on the oil cap or radiator cap?

A search shows that several others have had this occur as well. But I didn't notice any actual resolution to make it stop. Just to keep your oil and cap clean. Does not seem to be a catastrophic event, but you like to know whats going on. It seems some trucks gather more water than others.......

HAve you checked the intake side of the PCV as well for proper flow?

Water in the resonator? Is it possible you have a leak or bad air filter that is allowing water into the air intake system. It would leak down the PCV tube from the resonator from there.

Is the airbox and ducting stock? Any water in the airbox? Is the water clean, or oily?

What about a leak where the dipstick enters the pan? Or other seal leak in the southern hemisphere of the engine. Though you would think you would blow oil out too. Just spitballing on that one.

When you drained the oil, was it milky? Did you let it settle to see if the water separated, like in a glass jar or something?

The water in the resonator is the big thing for me. Which end did it come from?

If you dont see signs of wanter in the oil, it could be just enough to be trapped in the dipstick tube somehow, and just spoiling your readings. but how is it getting in there? Thats your question obviously.

Did you get my reply? I answered each of your thoughts within your response.

 

[Iarado]

Welcome to the Nation . . .
Looks like you have found some help.

 

[Dragon08]

You have officially exhausted all of my smarts. I guess that is why the other posters with similar conditions never seem to have a kill for it. The two culprits are the ones you have been looking at. A bad head gasket, which you believe you rules out with the oil tests and compression check. Great job getting objective data points. We are all glad that does not look like the root cause. The other is short trips and excessive condensation, especially in winter. Seems like your truck is one of those more prone to the issue.

That sludge is stubborn too, once it forms and finds its way to where it can congeal, like the fill cap or dipstick tube. Short of a 3ft Q tip, not sure of a good way to clean the dipstick tube. I have never gotten a good look at it to see if it can be removed and cleaned without a ton of effort. I am sure someone here has though.

There are a bunch of OBDII scan tools on Amazon that will read your temperature data. You can spend from 40 to 2000 bucks depending on the capability you need. The expensive units are 2 way communication and can command units to activate. Super useful if you are chasing something like a bad 4wd or ABS issue where several modules and sensors have to integrate their data to make miracles happen. The basic units are just readers and display the data on screen or via a phone app. I have the BlueDriver unit with app, and it does most of what I have asked of it. The thing I am missing is being able to activate the ABS unit for a better fluid flush. I have not missed it enough to spend another couple hundred buck though. yet.

 

[Dustnailer]

You have officially exhausted all of my smarts. I guess that is why the other posters with similar conditions never seem to have a kill for it. The two culprits are the ones you have been looking at. A bad head gasket, which you believe you rules out with the oil tests and compression check. Great job getting objective data points. We are all glad that does not look like the root cause. The other is short trips and excessive condensation, especially in winter. Seems like your truck is one of those more prone to the issue.

That sludge is stubborn too, once it forms and finds its way to where it can congeal, like the fill cap or dipstick tube. Short of a 3ft Q tip, not sure of a good way to clean the dipstick tube. I have never gotten a good look at it to see if it can be removed and cleaned without a ton of effort. I am sure someone here has though.

There are a bunch of OBDII scan tools on Amazon that will read your temperature data. You can spend from 40 to 2000 bucks depending on the capability you need. The expensive units are 2 way communication and can command units to activate. Super useful if you are chasing something like a bad 4wd or ABS issue where several modules and sensors have to integrate their data to make miracles happen. The basic units are just readers and display the data on screen or via a phone app. I have the BlueDriver unit with app, and it does most of what I have asked of it. The thing I am missing is being able to activate the ABS unit for a better fluid flush. I have not missed it enough to spend another couple hundred buck though. yet.

Hey Dragon, I like your 3' Q-tip Idea! I think it would sell big!😄 In all I think that I'm gonna have to live with this and that brings me to the "dovetail" story! and that is why I need see the oil on the dipstick. I have changed the oil twice in roughly 3,000 miles. The truck dose not burn or leak oil at all and this last change was about 2,000 mile and 2-1/2 quarts did not come out! So I put 5 qts back in and the sludge won't let me see ANY oil! BTW I swapped the filters too.

Also thanks for the scan tool tip, I will check those out as I retired last August, got through with the backed up honey do list and I am looking at flipping a car or two!

 

[Dragon08]

Yeah You have to figure out your true oil level. Disconnecting the tube and clearing it with some brake cleaner seems reasonable.

outside the box , what about wrapping the dip stick in pipe cleaners. Kindergarten style project. Maybe even soak them with some solvent. Obviously you have to make darn sure they won't get away from you.

I've pumped out pans through the dipstick tube. Worth a few minutes of ponder

 

[Talonxracer]

I would be greatly concerned about how much moisture induced sludge is packed into the oil passages and other critical areas.

 

[Dustnailer]

I would be greatly concerned about how much moisture induced sludge is packed into the oil passages and other critical areas.

Actually I did clean the oil sludge out of the dipstick tube 2 changes ago, I dumped Seafoam down through it an drove it around a bit to clean things up. My son thinks there is sludge in the oil pan that is keeping oil from draining?? I dunno? What did you use to suck oil out through the dipstick tube?

 

[Dragon08]

If there is a sludge build up in the pan, then that makes Talonxracer's comment very relevant. A sludge accumulation would indicate that the previous owner didn't mind the maintenance routine as much as you are. The best way to attack that is to drop the pan and wipe it out, but that is a task. That does not address any blockages in the top end, but you feel the truck is running smoothly as is, just has this foaming issue. You could:
Perform and engine flush with your choice of product. Seafoam, Moly, MMO, whatever. or
Drain the oil (again), reinstall the drain plug, and put your solvent down the dipstick tube so it does directly to the pan. Let it sit in there for a while, then drain with the front end up to make sure it all comes out. Then chase it with a qt of oil to flush out the solvent as much as possible. Then refill with 5 fresh qts of your synthetic of choice. (It is 5 qts for a 4cyl right?) At least that way you know your pan is empty,and your readings will be true.
I have never heard of enough sludge to prevent draining completely, but I don't work at a Toyota dealership.

Now here is the * on an engine flush with a buildup of sludge. You could end up freeing up some chunks that will not flush out and they will want to find your pick up tube. You could also clean up some sludge that is assisting worn out seals, and start a leak. I have never had those problems with the 2 engine flushes I have done in my life, but the internet is a scary place.

And none of this theorizing addresses the moisture problem directly. This was all just in response to your son's idea.

I have a hand pump from HF that I use to pump out my trans fluid. It was like $10. Very handy for differentials too! I just added some vinyl tuning to the suck end of the pump that slides down the dipstick tube until it finds bottom. Not a perfect solution by any means, but it works.

To be honest, I'd probably just keep doing what you are doing. Cut the oil change interval in half, always drain it hot, and fill with a high quality synthetic that will reduce the amount of moisture absorbed.

Check this out:

https://www.amazon.com/dp/B0894K1CN4/ref=sspa_dk_detail_3?psc=1&pd_rd_i=B0894K1CN4&pd_rd_w=Y5j6V&pf_rd_p=7d37a48b-2b1a-4373-8c1a-bdcc5da66be9&pd_rd_wg=GDS69&pf_rd_r=9NG3ASTEDCCTGEKSBN55&pd_rd_r=e76d696b-04bc-45f3-9b9f-616da7149d04&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExQkRNVTI0T1gzT1ZaJmVuY3J5cHRlZElkPUEwNDU5ODM1MjlFWjQ0V1JDNjU1MCZlbmNyeXB0ZWRBZElkPUEwOTc0OTMzM0NYRUk1WlI3SzFPTCZ3aWRnZXROYW1lPXNwX2RldGFpbCZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

Clean that tube and cap often, and hopefully your improved maintenance routine will reduce the foaming.

 

[Dustnailer]

If there is a sludge build up in the pan, then that makes Talonxracer's comment very relevant. A sludge accumulation would indicate that the previous owner didn't mind the maintenance routine as much as you are. The best way to attack that is to drop the pan and wipe it out, but that is a task. That does not address any blockages in the top end, but you feel the truck is running smoothly as is, just has this foaming issue. You could:
Perform and engine flush with your choice of product. Seafoam, Moly, MMO, whatever. or
Drain the oil (again), reinstall the drain plug, and put your solvent down the dipstick tube so it does directly to the pan. Let it sit in there for a while, then drain with the front end up to make sure it all comes out. Then chase it with a qt of oil to flush out the solvent as much as possible. Then refill with 5 fresh qts of your synthetic of choice. (It is 5 qts for a 4cyl right?) At least that way you know your pan is empty,and your readings will be true.
I have never heard of enough sludge to prevent draining completely, but I don't work at a Toyota dealership.

Now here is the * on an engine flush with a buildup of sludge. You could end up freeing up some chunks that will not flush out and they will want to find your pick up tube. You could also clean up some sludge that is assisting worn out seals, and start a leak. I have never had those problems with the 2 engine flushes I have done in my life, but the internet is a scary place.

And none of this theorizing addresses the moisture problem directly. This was all just in response to your son's idea.

I have a hand pump from HF that I use to pump out my trans fluid. It was like $10. Very handy for differentials too! I just added some vinyl tuning to the suck end of the pump that slides down the dipstick tube until it finds bottom. Not a perfect solution by any means, but it works.

To be honest, I'd probably just keep doing what you are doing. Cut the oil change interval in half, always drain it hot, and fill with a high quality synthetic that will reduce the amount of moisture absorbed.

Check this out:

https://www.amazon.com/dp/B0894K1CN4/ref=sspa_dk_detail_3?psc=1&pd_rd_i=B0894K1CN4&pd_rd_w=Y5j6V&pf_rd_p=7d37a48b-2b1a-4373-8c1a-bdcc5da66be9&pd_rd_wg=GDS69&pf_rd_r=9NG3ASTEDCCTGEKSBN55&pd_rd_r=e76d696b-04bc-45f3-9b9f-616da7149d04&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExQkRNVTI0T1gzT1ZaJmVuY3J5cHRlZElkPUEwNDU5ODM1MjlFWjQ0V1JDNjU1MCZlbmNyeXB0ZWRBZElkPUEwOTc0OTMzM0NYRUk1WlI3SzFPTCZ3aWRnZXROYW1lPXNwX2RldGFpbCZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

Clean that tube and cap often, and hopefully your improved maintenance routine will reduce the foaming.

Hey, I like you suggestion to just keep the maintenance going and I will add some prayers to that too! I am just concerned if I am running 2 quarts over full! I know that crowds the crankcase. One other question, you mentioned Toyota? Did they make the engines for these trucks? (5qts is the fill amount on the 4cyl)

 

[Kenzen]

Toyota is notorious for engine sludge problems.

 

[Dustnailer]

Toyota is notorious for engine sludge problems.

Ok, I just didn't get the Toyota thing, thanks!

 

[Dragon08]

Being overfilled doesn't do anything any good, that is certain. I say order up that tubing brush, or one similar, so you can get a good reading out of the dipstick. That way you can check that box and be sure you are in spec.
Once a week or so, clean the tube and cap again to try to reduce any buildup.
Do your best to avoid short trips that do not allow the engine to get up to temperature, as we are guessing that it's where the condensation is happening . This time if year is your worst case. Here in Michigan it has been very slushy and damp lately.
Your truck will still treat you well, it just has some special needs.

 

[Dustnailer]

Being overfilled doesn't do anything any good, that is certain. I say order up that tubing brush, or one similar, so you can get a good reading out of the dipstick. That way you can check that box and be sure you are in spec.
Once a week or so, clean the tube and cap again to try to reduce any buildup.
Do your best to avoid short trips that do not allow the engine to get up to temperature, as we are guessing that it's where the condensation is happening . This time if year is your worst case. Here in Michigan it has been very slushy and damp lately.
Your truck will still treat you well, it just has some special needs.

Thanks for all the good advice Dragon! I will look into the brush and wish me happy special needs trails!

 

[Dragon08]

Post back in the spring and let us know if the warmer temps reduce the issue. Just curious, what oil do you have in the engine now? Did the previous owner let you know what oil he ran in it when he started noticing the issue?

We all have our quirks, right.

 

[Iarado]

Back "in the day" we used to drain the oil, change oil filter, and refill with transmission fluid.
Fire it up and just let it idle for 15-30 minutes. Redrain while warm and change the filter again.
I've done this on two vehicles and know another guy that did it three times on the same vehical
before the sludge was gone.