Blowby advice

[Whitaker717]

Ok guys I’m at a crossroads with my truck. Been trying to de ide go sell it or keep sinking money into it. I have a 168K miles on my second engine. This is what my air filter looks like. When I pulled it out it was soaked with oil and water or condensation to the point it was dripping water. I didn’t see any coolant though. I pulled the rear ccv hose and cleaned it and I put my finger over the I'm and have great suction. I have not done the compression test yet, but that’s next. I have also done cruisers valve cover mod and it still happens. On a side note,it smells like really bad exhaust. Maybe that’s normal I’m not sure. Compression test aside, does it seem like I am headed towards a rebuild? I know the test will give me the definitive results I believe but I’m not sure I want to spend the money on a rebuild. Thanks guys. 

[89 MJ]

It having water in it is a weird issue. I suspect that’s a different issue all together. 
 

The compression test is the next step, like you said. That will really dictate if you need a rebuild or not. It does not have enough miles to where I would say the engine needs rebuilt. Maintenance is important here though. 
 

The exhaust will stink if you have no catalytic converter or have bad gas. It might also smell weird if there is coolant getting into the combustion chamber (should smell slightly sweet and you’d have white smoke) or it would smell if oil is being burned, which you’d also see in the form of a blue cloud. 
 

What does your oil consumption look like between oil changes? 

[Whitaker717]

19 minutes ago, 89 MJ said:

It having water in it is a weird issue. I suspect that’s a different issue all together. 
 

The compression test is the next step, like you said. That will really dictate if you need a rebuild or not. It does not have enough miles to where I would say the engine needs rebuilt. Maintenance is important here though. 
 

The exhaust will stink if you have no catalytic converter or have bad gas. It might also smell weird if there is coolant getting into the combustion chamber (should smell slightly sweet and you’d have white smoke) or it would smell if oil is being burned, which you’d also see in the form of a blue cloud. 
 

What does your oil consumption look like between oil changes? 

I do seem to lose some coolant somehow. Although I can’t tell where it’s going. Oil consumption doesn’t seem too bad but I’m guessing down maybe a quart over a 3k mile oil change. I do have a catalytic converter, new in the last 2 years. I have a lot of white steam out the exhaust pipe and quite a bit of condensation along with it. 

[89 MJ]

Just now, Whitaker717 said:

I do seem to lose some coolant somehow. Although I can’t tell where it’s going. Oil consumption doesn’t seem too bad but I’m guessing down maybe a quart over a 3k mile oil change. I do have a catalytic converter, new in the last 2 years. I have a lot of white steam out the exhaust pipe and quite a bit of condensation along with it. 

Is the steam out of the exhaust all of the time, even when it’s up to temp?
I’d call that oil consumption fairly normal. If you’re losing coolant and the exhaust is always a white cloud, it sounds like you’re getting coolant in to the combustion chamber somewhere. 
I’d double check both sets of lines on the valve cover to make sure that they’re hooked up in the correct locations and that they’re not clogged. 

[Whitaker717]

5 minutes ago, 89 MJ said:

Is the steam out of the exhaust all of the time, even when it’s up to temp?
I’d call that oil consumption fairly normal. If you’re losing coolant and the exhaust is always a white cloud, it sounds like you’re getting coolant in to the combustion chamber somewhere. 
I’d double check both sets of lines on the valve cover to make sure that they’re hooked up in the correct locations and that they’re not clogged. 

The white steam stops about a block down the road. I just did my oil change and cleaned both hoses of the ccv system. They had that white junk in them but not bad. If it’s leaking coolant in there how do you stop it?

[Pete M]

can't stop it until you find out where it's leaking.   compression test and a leakdown test will help in this endeavor.  

[Whitaker717]

8 minutes ago, Pete M said:

can't stop it until you find out where it's leaking.   compression test and a leakdown test will help in this endeavor.  

Yeah I’m heading that way Pete. 

[Ωhm]

Did you inspect/clean the 2.6mm orifice?

 

[Whitaker717]

4 minutes ago, Ωhm said:

Did you inspect/clean the 2.6mm orifice?

 

Yes 

[Ωhm]

[75sv1]

My thoughts: You have a blown head gasket. Hence the extra water. I could be wrong. I hope I am. I did have blow-by in my '88. My issues was getting a good seal on the valve cover. I'd use one of the Fel-Pro rubber or is it silicone ones. Their about $35. The cork ones would collapse on my in a few weeks. I'd got to a later Valve cover. The first time, I went to an early HO one, 91-95. Then I went to a ZJ 93-95 valve cover. Sort of a hybrid of the oil towers and the late style CCV grommets.  Or you could try the late style steel valve cover. I think they control the blow-by gasses the best. I run the ZJs on my '00 XJ. I ran one on my '98 XJ. That is with the Cruiser mod. 

         Do you know your engine temps? Since it has been cold, there might be more water vapor. I'm dealing with an LS 5.3 in an Avalanche. So, reading on the PVC system and oil catch cans. Seems in the winter, you have to 'service' the catch can a bit more. A lot more water gets into the system. 

[89 MJ]

3 hours ago, 75sv1 said:

My thoughts: You have a blown head gasket. Hence the extra water. I could be wrong. I hope I am

This was what I was thinking too. Or depending on the year, a cracked head. 
 

I think a catch can might be a good idea too. Just need to remember to empty it periodically. 

[75sv1]

1 hour ago, 89 MJ said:

This was what I was thinking too. Or depending on the year, a cracked head. 
 

I think a catch can might be a good idea too. Just need to remember to empty it periodically. 

Also, thinking to check the spark plugs. If one of them or a few are clean, then cracked head or head gasket. I don't think a catch can would fit the amount the OP is getting into the system. If it was just oil, then the CCV system might be out of whack. Yes, I did deal with this with my '88 MJ. One guy thought I had blown my engine. I haven't run a catch can. I do have one for my Avalanche. I'll see how it goes.

[89 MJ]

24 minutes ago, 75sv1 said:

Also, thinking to check the spark plugs. If one of them or a few are clean, then cracked head or head gasket. I don't think a catch can would fit the amount the OP is getting into the system. If it was just oil, then the CCV system might be out of whack. Yes, I did deal with this with my '88 MJ. One guy thought I had blown my engine. I haven't run a catch can. I do have one for my Avalanche. I'll see how it goes.

Good call. I have heard that the PCV or CCV is important to keep because it will help prevent rust due to condensation, but I also haven’t done any research on the matter. I agree that there are other problems that need fixed first for OP’s truck. 

[75sv1]

The RENIX has a bunch of tubes in the front. I do not know the functions in the block, that the front tube of the Valve Cover goes into, then into the Airbox. If there is a leak from some part or an obstruction, then oil in the airbox. I have suggested a valve cover filter like on hot rods, in the past. Some say that might mess with the MAF sensor or such. Still, might be a temporary fix. Then again, it depends in what State you are in. Also, the late model XJs had a larger CCV tube and fitting. I did adapt that and a '95 VC to my '88 MJ. 

[pizzaman09]

4 hours ago, 75sv1 said:

The RENIX has a bunch of tubes in the front. I do not know the functions in the block, that the front tube of the Valve Cover goes into, then into the Airbox. If there is a leak from some part or an obstruction, then oil in the airbox. I have suggested a valve cover filter like on hot rods, in the past. Some say that might mess with the MAF sensor or such. Still, might be a temporary fix. Then again, it depends in what State you are in. Also, the late model XJs had a larger CCV tube and fitting. I did adapt that and a '95 VC to my '88 MJ. 

RENIX utilizes a MAP sensor instead of a MAF.  That said, vacuum leaks are not helpful to either.

[Whitaker717]

On 2/17/2025 at 6:31 AM, 75sv1 said:

My thoughts: You have a blown head gasket. Hence the extra water. I could be wrong. I hope I am. I did have blow-by in my '88. My issues was getting a good seal on the valve cover. I'd use one of the Fel-Pro rubber or is it silicone ones. Their about $35. The cork ones would collapse on my in a few weeks. I'd got to a later Valve cover. The first time, I went to an early HO one, 91-95. Then I went to a ZJ 93-95 valve cover. Sort of a hybrid of the oil towers and the late style CCV grommets.  Or you could try the late style steel valve cover. I think they control the blow-by gasses the best. I run the ZJs on my '00 XJ. I ran one on my '98 XJ. That is with the Cruiser mod. 

         Do you know your engine temps? Since it has been cold, there might be more water vapor. I'm dealing with an LS 5.3 in an Avalanche. So, reading on the PVC system and oil catch cans. Seems in the winter, you have to 'service' the catch can a bit more. A lot more water gets into the system. 

This is my second engine in the truck and the head gasket has been replaced in say the last 2 years. I do wonder about a cracked head somewhere though. With this truck it’s really hard telling what it may be. I was going to do the compression test when it gets a bit warmer. With all the work I have had done to it, I am just stumped. When it’s cold like this I can barely get up to 170. Of course it’s almost below zero where I am. 

[75sv1]

OK, 170 is an issue. Some say to run at 180 F. I like 200 to 205. I think two things. First replace the radiator cap, if not done in the past 5 years. Second, replace the thermostat. Not sure what is good at the parts stores anymore. I have a stash of some old makes. Carrol is one of them. They fit, yet have to trim the gasket a bit. 

[75sv1]

Also, might try putting a sheet of cardboard in front of the radiator. Try to block the front grill off.

[Whitaker717]

1 hour ago, 75sv1 said:

OK, 170 is an issue. Some say to run at 180 F. I like 200 to 205. I think two things. First replace the radiator cap, if not done in the past 5 years. Second, replace the thermostat. Not sure what is good at the parts stores anymore. I have a stash of some old makes. Carrol is one of them. They fit, yet have to trim the gasket a bit. 

It’s actually less than 170. It’s only 4 degrees this morning. It has the closed system so there is no radiator cap per se. The thermostat has also been replaced in the last 2 years although I still feel it’s not quite functioning correctly. I’d like to get a 200 to 205 thermostat. Someone else said something about the cardboard too. I may just try that. On my drive this morning , I barely made it to 150 I bet. It’s really cold here though. My heater core is brand new too so I would think the heat should cook me out of that little truck but it never does. 

[75sv1]

I've had two 1 year old thermostats fail on me. One was a Mr. Gasket. The other a Motor Rad. Yeah, not fun, when temps don't get up enough to heat the cabin. I try and get NOS off of Ebay. I try to get a 193F to 197F. The RENIX system does have a pressure release as in the cap of the Purge bottle. Other might help you on that. Or if needed. Some convert to an open system. Placing the Radiator cap inline with the top radiator hose. What is your location?

[AZJeff]

Your engine is running WAY to cold, even accounting for the near zero temperatures.

 

replace the T’stat with a known good one set for 195*. Also, make sure your cooling system is holding pressure as designed.

[Whitaker717]

1 hour ago, 75sv1 said:

I've had two 1 year old thermostats fail on me. One was a Mr. Gasket. The other a Motor Rad. Yeah, not fun, when temps don't get up enough to heat the cabin. I try and get NOS off of Ebay. I try to get a 193F to 197F. The RENIX system does have a pressure release as in the cap of the Purge bottle. Other might help you on that. Or if needed. Some convert to an open system. Placing the Radiator cap inline with the top radiator hose. What is your location?

Central Illinois

 

[Whitaker717]

4 minutes ago, AZJeff said:

Your engine is running WAY to cold, even accounting for the near zero temperatures.

 

replace the T’stat with a known good one set for 195*. Also, make sure your cooling system is holding pressure as designed.

Any good recommendations for a 195 degree thermostat or higher?

[75sv1]

OK, I'm in Indiana. So, basically, the same weather. It would be OK to run a 205 F. I still prefer a 193 to 197F. My Xjs run about 205 F in the Summertime. Once your T-stat is fully open, your system will rise to its cooling efficiency level or Temp. So, the T-Stat sort of control the low side of the Temp. What I am hoping, is your T-Stat is in Failed Open or broke apart. Thus in Failed open mode. So, the oil is not getting warm to hot enough to boil off water. So, possibly adding to much moister into the blow by or emissions. Its a stretch. 

      Check your oil. Is it clear or even a bit off color, or  dark brown or even black? Then ok. If milky brown, then it is getting water in it. I'd check the spark plugs. I might try a Valve Cover breather for a temp fix. Still, be aware it might affect Idle and acceleration.