87 Jeep Cherokee Inline 6, REALLY bad blow by
Marantz
03-09-2006, 02:50 AM
Yeah, what the title says. I purchased this jeep not to long ago, and it has some really bad blow by, so bad, that it will soak an aircleaner in a week with oil.
The previous owners step dad used an STP bottle to catch the oil, but the previous owner replaced all the hoses and vaccum lines and such, and took out the STP bottle.
They used some ring\seal treatment, and it has slowed it down quite a bit, but for how long I have no idea.
I know theres only a few ways to fix this problem, and I know its pretty bad, but to be honest, it still has lots of power. The gas mileage is crap, but its still not TOO bad..
Basicly what I'm asking is, how much is it to fix? What are all of my options? I was thinking of having it rebuilt, or possibly just a new motor. What am I looking at?
The previous owners step dad used an STP bottle to catch the oil, but the previous owner replaced all the hoses and vaccum lines and such, and took out the STP bottle.
They used some ring\seal treatment, and it has slowed it down quite a bit, but for how long I have no idea.
I know theres only a few ways to fix this problem, and I know its pretty bad, but to be honest, it still has lots of power. The gas mileage is crap, but its still not TOO bad..
Basicly what I'm asking is, how much is it to fix? What are all of my options? I was thinking of having it rebuilt, or possibly just a new motor. What am I looking at?
Marantz
03-09-2006, 03:03 AM
Actually, I just did some searching (I should have searched first...jeeze...I'm a forum admin somewhere else..) and I found an answer that I will try out
http://www.automotiveforums.com/vbulletin/showthread.php?t=432608&highlight=ccv+hose
There ya go folks :grinyes:
Now one more quick question...
whats ccv stand for :( Crank Case Ventilation.....yeah...I kinda figured it out
http://www.automotiveforums.com/vbulletin/showthread.php?t=432608&highlight=ccv+hose
There ya go folks :grinyes:
Now one more quick question...
whats ccv stand for :( Crank Case Ventilation.....yeah...I kinda figured it out
Saudade
03-09-2006, 09:12 AM
It depends on what's causing it. As you've discovered, clogged "plumbing" can prevent enough vacuum from forming and allow oil to backflow into the air cleaner. This "plumbing" includes the areas under the valve cover around the 2 grommets. Also, check that big vacuum junction at the front of the block. There's a seal there are well. Since you have a lot of oil in the aircleaner, there's likely a bit of oil on it too.
However, if the problem is caused by worn piston rings, then there is too much combustion pressure leaking into the crankcase, offsetting the vacuum. You need to do a compression test to verify. If this is the source, I doubt any tweaking the CCV system will overcome it without affecting engine operation. Some people patch a collection can into the hose from the valve cover to the airbox with a drain in the bottom to reduce the oil in the aircleaner (kind of homemade oil separator).
Mine was a clogged CCV tube. It did draw vacuum but not enough. I used a drill bit to clean the metered orifice, but not enlarge it. I also ran a wire inside the tube and flushed it with carb cleaner. I also changed the front grommet and elbow that connects to the tube that leads to the airbox. Mine's all better now. ;)
However, if the problem is caused by worn piston rings, then there is too much combustion pressure leaking into the crankcase, offsetting the vacuum. You need to do a compression test to verify. If this is the source, I doubt any tweaking the CCV system will overcome it without affecting engine operation. Some people patch a collection can into the hose from the valve cover to the airbox with a drain in the bottom to reduce the oil in the aircleaner (kind of homemade oil separator).
Mine was a clogged CCV tube. It did draw vacuum but not enough. I used a drill bit to clean the metered orifice, but not enlarge it. I also ran a wire inside the tube and flushed it with carb cleaner. I also changed the front grommet and elbow that connects to the tube that leads to the airbox. Mine's all better now. ;)
Marantz
03-10-2006, 12:38 AM
Well I cleaned some things up.
Except, the hose running from the top of the valve cover, to the air box, does not have a vaccum...in fact...if I cover it with my finger, it builds up pressure, when I take my finger off, poof, releases it.
...uh...any ideas?
Except, the hose running from the top of the valve cover, to the air box, does not have a vaccum...in fact...if I cover it with my finger, it builds up pressure, when I take my finger off, poof, releases it.
...uh...any ideas?
Saudade
03-11-2006, 11:10 AM
OK, let's try again.
First, you should do a compression test to see if any cylinders are too "leaky". If you have poor compression, then this is most likely the cause of your blowby. There is not much you can do about it, short of a rebulid.
If your compression is OK, remove the valve cover and clean the insides around the grommet opening. You may even need to replace the grommets/elbows as portions of them extend into the valve cover.
First, you should do a compression test to see if any cylinders are too "leaky". If you have poor compression, then this is most likely the cause of your blowby. There is not much you can do about it, short of a rebulid.
If your compression is OK, remove the valve cover and clean the insides around the grommet opening. You may even need to replace the grommets/elbows as portions of them extend into the valve cover.
Automotive Network, Inc., Copyright ©2024