Dipstick popping out
#1
Dipstick popping out
Hi all. New here and not super experienced. I bought a '92 XJ 4.0 that (supposedly) only needed a fuel pump. It did not start and I don't know how long it's been sitting since it last ran. After I replaced the fuel pump, I tried starting the car and the engine was turning over, but then all of a sudden the dipstick popped out and smoke started coming out of the dipstick hole. This happened both before and after an oil change and oil filter replacement. I don't think any oil was coming out of the hole, just smoke. Any ideas as to why this is happening?
#4
CF Veteran
Joined: Jun 2016
Posts: 2,138
Likes: 278
From: Santa Clarita California
Year: 2001
Model: Cherokee (XJ)
Engine: 4.0L
maybe , it sounds like the rings may be stuck and the engine has a lot of blow by that's the compression going right by the rings . you mite want to put some trans oil in the cylinders and let it sit over night before you try to start it again .
#6
Yep... "Blow by". Compression is pressurizing the crankcase for some reason. Either a blockage in the Crankcase ventilation system like s346k mentioned or a massive compression leak. And you are right... The only way to see how bad it is would be to remove the oil fill cap and see how much there really is. If it's puffing good there is a major issue for sure.
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#8
Stuck piston rings make sense. I think I will go ahead and let them soak overnight. Is trans oil the best fluid for the job? I've also read people use seafoam, diesel, Marvel's Mystery Oil, penetrating oil, or a combination of these. I'd like to use the most aggressive treatment. What do you guys think?
#9
CF Veteran
Joined: Oct 2011
Posts: 1,394
Likes: 8
From: SEMO
Year: 2000
Model: Cherokee (XJ)
Engine: 4.0 L6
MMO would be my fluid of choice. It has an oil base, rather than a straight solvent like Seafoam. If you need something stronger, penetrating oil would be OK.
Be sure that the CCV system has no clogs in it before assuming this is due to stuck rings.
Be sure that the CCV system has no clogs in it before assuming this is due to stuck rings.
#11
Alright sounds good, thanks for all your advice guys. I think I'll first replace that CCV elbow and hose. If that's fine I'll do an MMO soak with a generous amount of oil (maybe with a bit of penetrating oil mixed in) for a good 24 hours and try starting it afterward. I'm really hoping it's the CCV valve or stuck piston rings rather than something deeper.
#12
How much fluid would you guys put down the plug holes and into the cylinders to free up the rings? I poured almost a liter down one of the plug holes because I read elsewhere that you should fill until you see the fluid flowing back out... Now I'm worried that was way too much.
Last edited by PDXJ40; 02-04-2018 at 11:21 PM.
#13
How much fluid would you guys put down the plug holes and into the cylinders to free up the rings? I poured almost a liter down one of the plug holes because I read elsewhere that you should fill until you see the fluid flowing back out... Now I'm worried that was way too much.
But you haven't hurt anything yet as long as you don't try to put the plugs back in and start it with that much in there. I would think about a half a cup per cylinder would be enough. Then let it soak and drain down past the rings for a couple days.
After this you will want to turn it over BY HAND with the plugs still out at least two full revolutions before you put the plugs back in and try to start it. It is important that there is no more, or very little liquid left in the cylinders before it is turned over fast with the starter.
Did you check the Crankcase ventilation? Was it clear?
#14
How much fluid would you guys put down the plug holes and into the cylinders to free up the rings? I poured almost a liter down one of the plug holes because I read elsewhere that you should fill until you see the fluid flowing back out... Now I'm worried that was way too much.
#15
Curious? do you read any of the other replies that have already been shared at all?