"Foam" on inside of oil filler neck??

Messages
1,199
Location
Arkansas
Yesterday I spent the afternoon washing and polishing my wife's Pontiac Grand Prix GTP. I switched to Mobil 1 back in the Summer, and I did the 2nd oil change on M1 two weeks ago. I decided to take a peek through the oil filler tube to see how the inside of the engine was looking. I took the cap off, and I noticed a yellowish, foamy or soapy looking substance on the inside of the oil tube. I checked the oil, and it looked fine. The level was still full as well. The first thing I thought about was a blown head gasket. However, the coolant level is still fine, and the car has not been running hot, at least not the last time I drove it on Monday. The film was not on the tube when I changed the oil two weks ago. The only thing I did different was to susbstitute a qt. of 15w50 M1 instead of all 10w30. I did not smell the oil on the dipstick. I wiped the foam off the filler tube, and the oil on the rag I used didn't smell like coolant. It smells a little maybe a little "varnishy" to me. So what do ya'll think the deal is? My wife and I took my car last night, but we plan on driving the GTP today. Yesterday was the first time I've driven the car since Monday, and it was only for a short hop. I really didn't pay any attention to the temp gauge,and the car seemed to run just as well as usual. My wife does know to watch her gauges, but she hasn't said anything about the car running hot or anything. I've only seen this on old sludged up engines before,but this "foam" looks different from that though. This is really puzzling me.
 

KW

Messages
1,686
Location
Central Arkansas
I may just be from moisture in the filler tube. My '65 Chevy used to do that in the cooler months when I had a filler tube type intake on it. That area will see a lot of vapor and not much heat. Just wipe it out and press on.
 
Messages
56
Location
League City, TX
I've got a Dakota with the 4.7 v8, and I think I know what you are talking about. On my engine, the oil fill tube is actually a tube that bolts to the side of the block, rather than a cap on top of the valve cover. On my engine, as has been noted on this engine as being an issue, if you look at the top of the tube, you'll see what I call yellow "snot" forming. This is caused by moisture condensation in the tube as the engine cools down. I've seen quite a bit of water behind my fill cap when I've checked it. Chrysler added a baffle into the tube to keep the tube at a higher temp, to help alleviate the condensation, but mine does it after time. I clean it whenever it needs it. The snot can't really drain down to the pan, due to the baffle, supposedly. However, when I changed my oil last, I noticed a small yellow line coming out with the oil which looked to me like moisture. I do a lot of short trip driving, 4 miles one way, so my oil doesn't get hot very often, which won't allow the moisture to burn off very well. I'll be installing an Amsoil remote bypass very soon-already have it, so maybe it'll remove some of that moisture.
 
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3,845
I forgot to mention this and it has been an issue in the VW/Audi gasoline 4 cylinders of late. That is your engine just maybe operating too cool. I just came in from repairing a New Beetle with a bunch of white water spooge in the breather/oil filler cap area with a stuck open thermostat. Cheers.
 
Messages
9,448
Location
USA
TECH, I had a '01 4.7 Dak QC SLT+ 4x4. I too experinced this. I found that switching to M1 helped. I also found out that if I drove it a bit more that aleviated alot of it. My wife was the primary driver after the first year and she simply did not get it up to temp with her short around town diveing. When I was driveing it 80+ miles a day on the highway this was not an issue. I made sure to drive it about 60 miles each weekend on the highway and this combined with M1 solved this problem completely for me. I did not know about Lube Control back then or I would have tried that as well.
 
Messages
56
Location
League City, TX
John, I agree that longer trips will help burn off the moisture, but the moisture forms while the engine cools down, so you'd have to routinely drive a while to keep the buildup of snot down-something that I can't do with mine, unless I want to drive aimlessly, and that isn't going to happen. Get this. I changed my oil over to Amsoil 5w30 just last week, a few days ago. I cleaned my oil fill cap, and around the neck area, which had a decent amount of snot built up, mostly on the backside of the cap. Today, I pulled the cap back off, and there is a glob of yellow snot on the top of the fill tube! I need to do something about this. I shook the freaking cap, which has a small vent hole on the bottom, and water drops shake out of it. This cap is about 2 inches thick, with a hollow chamber inside. I pulled the cover off of it from the backside, and there is just empty space. I wonder if I was to leave that cover off of the cap, if the moisture would not form as much, or maybe it would simply drain down into the engine. Another thing I could do is fill that area with a sponge, or foam, to absorb moisture. What I'm actually going to do though, is route the return line of my bypass filter to the cap, which I'm in the middle of now. That would keep the neck clean if nothing else. Hopefully the bypass will keep the water out of my oil.
 
Messages
567
Location
Daytona Beach
Tech, Your problem is the short trips. It won't make any difference which oil you use, if you don't get the oil temp up, in these ambient temps, you will get condensation. The yellow "mayonaise" is harmless where it is, as you said, the oil looks good. The additives will tend to keep the moisture "neutralized" (TBN) and in a safe place until you DO get the engine hot.
 
Messages
3,845
Common issue with that engine and others, including BMW a few years ago.. Consider using Lube Control which eliminates moisture at at least 1 ounce LC to 1 Qt oil capacity. A quick and low cost fix. Do analyze the oil to make sure the condensation isn't affecting the rest of the system without you knowing it. And [Welcome!] TECH ! Glad to have another pro mechanic on board.
 

Racerjk

Thread starter
Messages
1,199
Location
Arkansas
Ok,my wife has a 1.5 mile drive to work. The temp never got much above 40 until Thursday. As a matter of fact, it was in the mid 30's most of the time. I'm not sure how long she lets the car warm up before she leaves for work. I guess the short trips combined with the cold weather could be the cause!
 
Messages
9,448
Location
USA
Tech, You have the fix already in place. DC's fix was to hide it with that baffle and to insert that plug into the cap closeing off the hollow section. I know a lot of guys that took their valve covers off to install H.O. Cams and KRC cams and the engines are as clean as can be inside. I also never say any trace of this stuff in my oil at all. I hever had more then a teaspoon of this stuff and that was at it's worst. You can either try Lube COntrol, drive the truck more or try a bypass filter system to absorb the moisture. If you are getting a strem of yellow in your oil I would think you had other problems. DO you have the yellow long life coolant or is your Red or green? I ask because DC has a H.O.A.T. yellow colored coolant I belive? I also belive that this engine uses airators to lube the cam and valve train quickly. Vaporized oil and moisture together is probably the cause of this. I would do a UOA and go from their. I doubt that you should be too concerned about this so long as it is not coolant leak. THese engines are Japanesse like with their low wear numbers!!! I like this engine so much that the engine was the decideing factor for me!! THe 4.7 V8 that DC is makeing right now is the best V8 design currently in use by a company that was once a domestic brand!! This engine design is better then Gen III, Northstar or 4.6 Modular Ford IMHO. Their are only a few things I would change and they are minor!
 
Messages
56
Location
League City, TX
quote:
Originally posted by JohnnyG: Tech, Your problem is the short trips. It won't make any difference which oil you use, if you don't get the oil temp up, in these ambient temps, you will get condensation. The yellow "mayonaise" is harmless where it is, as you said, the oil looks good. The additives will tend to keep the moisture "neutralized" (TBN) and in a safe place until you DO get the engine hot.
Yeah, I know about the short trips. I just used the o/c reference to indicate how QUICKLY this crap came back. I never noticed it come back that fast.
 
Messages
56
Location
League City, TX
quote:
Originally posted by JohnBrowning: Tech, You have the fix already in place. DC's fix was to hide it with that baffle and to insert that plug into the cap closeing off the hollow section. I know a lot of guys that took their valve covers off to install H.O. Cams and KRC cams and the engines are as clean as can be inside. I also never say any trace of this stuff in my oil at all. I hever had more then a teaspoon of this stuff and that was at it's worst. You can either try Lube COntrol, drive the truck more or try a bypass filter system to absorb the moisture. If you are getting a strem of yellow in your oil I would think you had other problems. DO you have the yellow long life coolant or is your Red or green? I ask because DC has a H.O.A.T. yellow colored coolant I belive? I also belive that this engine uses airators to lube the cam and valve train quickly. Vaporized oil and moisture together is probably the cause of this. I would do a UOA and go from their. I doubt that you should be too concerned about this so long as it is not coolant leak. THese engines are Japanesse like with their low wear numbers!!! I like this engine so much that the engine was the decideing factor for me!! THe 4.7 V8 that DC is makeing right now is the best V8 design currently in use by a company that was once a domestic brand!! This engine design is better then Gen III, Northstar or 4.6 Modular Ford IMHO. Their are only a few things I would change and they are minor!
Interesting, I have read about the baffle install, but didn't know about the cap cover. It appears that there is a LOT of condensation formed behind the cap. I like this engine as well. The main bearing "caps" is really interesting as well.... Anyways, I'll be drilling a nice hole in the cap today, and my bypass system will keep that crap clean. I think I'll do an analysis of my last o/c to see if it shows any water or antifreeze.....
 
Messages
2,480
I had some of this build-up a couple weeks ago when my thermostat went south. Replaced it and it went away on it's own. Maybe thermostat is not operating properly?
 
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