oil pressure problem
07-19-2014, 09:35 AM
#47
Seasoned Member
Thread Starter
Join Date: May 2010
Location: Ypsilanti, MI
Posts: 271
Likes: 0
Received 0 Likes
on
0 Posts
Year: 2001
Model: Cherokee
Engine: 4.0
07-19-2014, 09:38 AM
#48
Seasoned Member
Thread Starter
Join Date: May 2010
Location: Ypsilanti, MI
Posts: 271
Likes: 0
Received 0 Likes
on
0 Posts
Year: 2001
Model: Cherokee
Engine: 4.0
how do i get that cleaned out i know you are the oil guru so i need your opinion on this. Is seafoam something i should do? i'm very hesitant to do that on my engine 235000 miles and all.
07-19-2014, 11:21 AM
#51
Herp Derp Jerp
Join Date: Nov 2011
Location: Parham, ON
Posts: 18,251
Likes: 0
Received 13 Likes
on
12 Posts
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
There will generally only be metal in the oil if you bust a piston skirt, and you'd have to drop the pan to see it. You're looking for coolant and water in the oil. It should NEVER be red.
Also wondering what color your coolant is...
Also wondering what color your coolant is...
07-19-2014, 03:51 PM
#56
Seasoned Member
Thread Starter
Join Date: May 2010
Location: Ypsilanti, MI
Posts: 271
Likes: 0
Received 0 Likes
on
0 Posts
Year: 2001
Model: Cherokee
Engine: 4.0
07-20-2014, 06:22 AM
#58
Seasoned Member
Thread Starter
Join Date: May 2010
Location: Ypsilanti, MI
Posts: 271
Likes: 0
Received 0 Likes
on
0 Posts
Year: 2001
Model: Cherokee
Engine: 4.0
07-20-2014, 09:53 AM
#60
Banned
Join Date: Feb 2014
Location: Florida
Posts: 2,379
Likes: 0
Received 17 Likes
on
16 Posts
Year: 2000
Model: Cherokee(XJ)
Engine: Golen 4.6L
Do this. After I started sending samples off to Blackstone, I doubt I'll ever do another oil change without an oil test. They'll send you the collection kit for free.
Also, another test you can do to confirm or rule out head problems is to use a combustion leak tester to test for exhaust gas in your coolant. You can buy a combustion leak tester for about $50, but you can probably find a local mechanic who has one. It's a quick and easy test.
That ain't right. Is it kind of milky reddish brown? Is your oil level rising between oil changes?
Again, an oil analysis can tell you a lot about what's going on.
I had the 0331 head crack in my 2000 XJ. The symptoms were that it inexplicably ran hot sometimes (but not always), and changing out cooling system components never really solved the problem. The water pump failed, so I replaced it and flushed the system. Within a year after that I noticed brown sludge in my coolant, and the the water pump failed again. You can tell when a water pump fails by looking for coolant leaking from the weep hole directly underneath the pump, which will run down the lower hose. You might think you have a hose leak there, but if you see a leak there, it's probably coming out of the weep hole.
I thought I was having a bad run of luck with water pumps, but now I'm convinced it was the sludge that killed the second one. That sludge was a huge warning sign. It's not rust. It's the particulate matter that is left behind when coolant boils. I ended up replacing pretty much the entire cooling system before it was over, and the truck still intermittently ran hot.
Eventually I started seeing oil pressure problems like what you're describing, although I didn't get the rattle. I never saw the milky film under the oil cap people talk about, but the oil itself became lighter in color, more of a reddish brown. That turned out to be water in the oil.
I was never able to confirm what was the actual proximate cause of the low oil pressure. I did not get the rattle like you describe, but that rattle could be a failed cam bearing allowing the oil to flow past so that you lose pressure. The common cause of cam bearing failure is water in the oil, which is why some of us instantly thought 0331 head when you described your issue.
In my case, I was on a road trip when my oil pressure gave out, so I took it to a great old mechanic I had used when I lived in the town I was visiting. He took one look at my oil and said there was water in it. Then he used the combustion leak tester while I watched and confirmed the presence of exhaust gas in my coolant. He changed the oil and patched me up enough to limp back home.
So what was happening in my case was that there was a crack in the head between the number 3 and number 4 cylinders that would open up sometimes (but not always), spewing exhaust gas into my coolant and boiling it. That explained the intermittent overheating. The boiled coolant left behind that reddish brown sludge that was clogging up the system and killing water pumps. Eventually the crack opened up enough to start dumping enough water into the oil to cause problems there also.
This is why I say that an oil analysis and exhaust gas test will tell you a lot for not a whole lot of money. If I had been getting the oil analyzed all along, I probably would have been able to diagnose the problem a lot sooner and save myself a lot of unnecessary expense. If either test comes back positive, you know you have a head problem. Hopefully it's just a gasket and not the crack.
To be honest, I'm amazed that engine held up as long as it did under those circumstances. Good luck with yours.
Also, another test you can do to confirm or rule out head problems is to use a combustion leak tester to test for exhaust gas in your coolant. You can buy a combustion leak tester for about $50, but you can probably find a local mechanic who has one. It's a quick and easy test.
That ain't right. Is it kind of milky reddish brown? Is your oil level rising between oil changes?
Again, an oil analysis can tell you a lot about what's going on.
I had the 0331 head crack in my 2000 XJ. The symptoms were that it inexplicably ran hot sometimes (but not always), and changing out cooling system components never really solved the problem. The water pump failed, so I replaced it and flushed the system. Within a year after that I noticed brown sludge in my coolant, and the the water pump failed again. You can tell when a water pump fails by looking for coolant leaking from the weep hole directly underneath the pump, which will run down the lower hose. You might think you have a hose leak there, but if you see a leak there, it's probably coming out of the weep hole.
I thought I was having a bad run of luck with water pumps, but now I'm convinced it was the sludge that killed the second one. That sludge was a huge warning sign. It's not rust. It's the particulate matter that is left behind when coolant boils. I ended up replacing pretty much the entire cooling system before it was over, and the truck still intermittently ran hot.
Eventually I started seeing oil pressure problems like what you're describing, although I didn't get the rattle. I never saw the milky film under the oil cap people talk about, but the oil itself became lighter in color, more of a reddish brown. That turned out to be water in the oil.
I was never able to confirm what was the actual proximate cause of the low oil pressure. I did not get the rattle like you describe, but that rattle could be a failed cam bearing allowing the oil to flow past so that you lose pressure. The common cause of cam bearing failure is water in the oil, which is why some of us instantly thought 0331 head when you described your issue.
In my case, I was on a road trip when my oil pressure gave out, so I took it to a great old mechanic I had used when I lived in the town I was visiting. He took one look at my oil and said there was water in it. Then he used the combustion leak tester while I watched and confirmed the presence of exhaust gas in my coolant. He changed the oil and patched me up enough to limp back home.
So what was happening in my case was that there was a crack in the head between the number 3 and number 4 cylinders that would open up sometimes (but not always), spewing exhaust gas into my coolant and boiling it. That explained the intermittent overheating. The boiled coolant left behind that reddish brown sludge that was clogging up the system and killing water pumps. Eventually the crack opened up enough to start dumping enough water into the oil to cause problems there also.
This is why I say that an oil analysis and exhaust gas test will tell you a lot for not a whole lot of money. If I had been getting the oil analyzed all along, I probably would have been able to diagnose the problem a lot sooner and save myself a lot of unnecessary expense. If either test comes back positive, you know you have a head problem. Hopefully it's just a gasket and not the crack.
To be honest, I'm amazed that engine held up as long as it did under those circumstances. Good luck with yours.