Engine Rebuild

Kat Wheeler

New Member
Joined
May 30, 2021
Messages
3
Reaction score
1
Hi guys I’m new to owning Jeeps but i know my way around an engine. I just recently purchased a 2003 Jeep Liberty with 160,000 miles on it but it appears to have coolant in the oil. It drives fine but when at a stop it idles rough. Im assuming in a head gasket so my plan is to just rebuild the whole thing so i get as much use out of the car that i can. That being said what parts should I replace? I already plan on buying new heads or at least test the compression and replace whichever head seems to be cracked if any. Any advice would also be helpful too :)
 

LibertyTC

Well-Known Member
Staff member
Moderator
Joined
Oct 24, 2008
Messages
8,707
Reaction score
1,293
Location
B.C. Canada
Welcome to the forums.
Do not drive it with coolant in oil.
Do you happen to know if it had over heated? Best place to start is to pull both valve covers.
If you could post a few photos inside the covers, that would be helpful. You have the 3.7 engine I assume ?
Here is the 2003 factory service manual. This will be extremely helpful in the re-build process
https://colorado4wheel.com/manuals/Jeep/KJ/2003JeepKJServiceManual.pdf.
 

Kat Wheeler

New Member
Joined
May 30, 2021
Messages
3
Reaction score
1
Welcome to the forums.
Do not drive it with coolant in oil.
Do you happen to know if it had over heated? Best place to start is to pull both valve covers.
If you could post a few photos inside the covers, that would be helpful. You have the 3.7 engine I assume ?

yes 3.7 and no it hasn’t overheated. The guy i got it from said it was just condensation. Didn’t know the part where you put the oil pulls out and it was covered.
 

LibertyTC

Well-Known Member
Staff member
Moderator
Joined
Oct 24, 2008
Messages
8,707
Reaction score
1,293
Location
B.C. Canada
Is the oil on dipstick a Milky brown with bubbles?
Also under the oil fill cap is that clean or yellow gunk under oil cap?
I edited in the Factory manual above for you in post 2 above.
 

Kat Wheeler

New Member
Joined
May 30, 2021
Messages
3
Reaction score
1
There was a little bit on the dip stick when we test drove it. The guy i got it from said it was just condensation but when i got the car home and checked again the oil looked normal. Until i under the oil cap and it looked like expired chocolate milk
 

LibertyTC

Well-Known Member
Staff member
Moderator
Joined
Oct 24, 2008
Messages
8,707
Reaction score
1,293
Location
B.C. Canada
Personally I would not be driving in this unknown state. Coolant & oil can ruin a good engine quickly.
Pull one of the valve cover to start out with for an inspection. If it's a mess in the valve train area, it will need to be rebuilt.
You can post images ? I use IMGUR (copy & paste for forums) which is free & then post my photos directly here.
 

LibertyTC

Well-Known Member
Staff member
Moderator
Joined
Oct 24, 2008
Messages
8,707
Reaction score
1,293
Location
B.C. Canada
Clean off the bottom of the oil cap, there may also be a baffle below the cap that pulls upwards, & also check to make sure that the PCV valve on oil filler neck is clean.
To remove the PCV you need to remove the hose first. I use a hairdryer to heat the hose up first then gently pull hose backwards, while holding onto the pcv.
Then twist PCV counter clock wise from housing. It should rattle. Can use carb cleaner then replace.
 

Michael Wolfe

Member
Joined
Feb 14, 2021
Messages
52
Reaction score
17
Location
Erie, PA
Had this issue with the first Toyota V6 with faulty head gaskets. Replaced both head gaskets, water pump, thermostat, timing belt, idlers and adjuster, basically everything that was a service item, that I didn't want to have to tear down and replace anyway in 30K. If it's "simply" a failed head gasket, you should be able to see where the leak is, looks like ")(" across the sealing ring. You'll still have to check for warped heads with a straightedge, and the block machined surface. Being a 3.7, would replace the lash adjusters, and install the aftermarket clips which prevent the rockers from disengaging and flopping around under the valve cover. Rough idle could be many different issues, but one of them could be lash adjusters that aren't working properly.
 

WheelNut

Member
Joined
Feb 16, 2021
Messages
79
Reaction score
49
Location
Vancouver, BC
Drain the oil first to check it out before buying any parts. Moisture will indeed build up under the oil filler cap, and this is especially true if you only do short drives where the engine doesn't have time to stay hot for long and get rid of some of that moisture that in inside the engine. Oil change is cheap and easy, well, all easy except contorting your arm into a position to turn the oil filter, ha!
If there is any coolant in the oil it will reduce the oil's friction reducing capabilities which could turn a trip to work into a spun bearing.
 

Robochop

Robochop
Joined
May 16, 2017
Messages
33
Reaction score
11
Location
Virginia
I have done both, head gasket change and engine rebuilds. I would do a compression test first. If all cylinders seem the same, you can double check with a cylinder leak down test to determine a bad head gasket. If you need to replace the head gaskets I would do a top-end rebuild, including the timing chains, (First ensure the cylinders look good after removing the heads). Head gasket sets are available on ebay for about $250. Graphite Head Gasket Set Bolts Lifters Fit 02-05 Dodge Jeep Trucks 3.7 VIN K | eBay.
It is a lot of labor, especially in the car. I take the heads to a local machine shop. I bring them the new seals and lifters and let them do their thing! It usually runs about $300 unless there is an issue with the head. When shopping for the gasket set, you can usually find them to include the water pump as well. Mizumo Auto and Domestic Gaskets are the 2 ebay sites I have had the best luck with. Please let me know if you have any questions. I have plenty of pics if you need any and good luck!
 

uss2defiant

Full Access Member
Joined
Jun 25, 2014
Messages
3,567
Reaction score
139
Location
Tucson, Arizona
It may not be a head gasket issue.
The PCV on the early version KJ is at the oil filler neck and the foaming in the neck does occur at colder climates and/or multiple short trips.

Search the forum.
It's an actual TSB.

Unfortunately the parts for the TSB is no longer available.
 

Ronald

New Member
Joined
Nov 29, 2018
Messages
23
Reaction score
7
Location
New York
Hi guys I’m new to owning Jeeps but i know my way around an engine. I just recently purchased a 2003 Jeep Liberty with 160,000 miles on it but it appears to have coolant in the oil. It drives fine but when at a stop it idles rough. Im assuming in a head gasket so my plan is to just rebuild the whole thing so i get as much use out of the car that i can. That being said what parts should I replace? I already plan on buying new heads or at least test the compression and replace whichever head seems to be cracked if any. Any advice would also be helpful too :)
I HAVE A liberty WITH THE SAME ENGINE and it needed a water pump at 40K [ so you took a chance the with 160K mileage I guess you want to tear it down and check each part as you do because there are to many variable's for to give you a specific answer the other option is to find a wreck with a low mileage engine and search the yards around you and get the best price some even offer a guarantee with the used engines. Good Luck
 

Kal808

New Member
Joined
Feb 7, 2021
Messages
17
Reaction score
3
Hello,

I just recently had something similar happen to me. I ran a compression test to make sure. Sure enough low pressure in the chamber(can't remember which ones). I replaced the head gasket, cylinder head gasket, resurfaced the cylinder heads, changed the timing chains(all three), changed the water pump, and thermostat.
Total $3998.98 "DO NOT GO TO JEEP." they wanted $6000 just for the head gasket and, cylinder gasket(given I live in Hawaii) so everything cost a lot more.


Hi guys I’m new to owning Jeeps but i know my way around an engine. I just recently purchased a 2003 Jeep Liberty with 160,000 miles on it but it appears to have coolant in the oil. It drives fine but when at a stop it idles rough. Im assuming in a head gasket so my plan is to just rebuild the whole thing so i get as much use out of the car that i can. That being said what parts should I replace? I already plan on buying new heads or at least test the compression and replace whichever head seems to be cracked if any. Any advice would also be helpful too :)
 

flajeepdiver

New Member
Joined
Mar 3, 2020
Messages
8
Reaction score
2
Hi guys I’m new to owning Jeeps but i know my way around an engine. I just recently purchased a 2003 Jeep Liberty with 160,000 miles on it but it appears to have coolant in the oil. It drives fine but when at a stop it idles rough. Im assuming in a head gasket so my plan is to just rebuild the whole thing so i get as much use out of the car that i can. That being said what parts should I replace? I already plan on buying new heads or at least test the compression and replace whichever head seems to be cracked if any. Any advice would also be helpful too :)

Check the coolant overflow bottle for leaks and check the hoses going to and from it. It's in a bad spot so if it's leaking it goes into the engine and causes things like ignition coils and spark plugs to go bad. That's possibly how you got coolant in the engine. A 2003 might need a new bottle and hoses. The bottle is about 35 dollars for a new one.
 

MiloHunter

New Member
Joined
Jan 21, 2022
Messages
6
Reaction score
3
Drain the oil first to check it out before buying any parts. Moisture will indeed build up under the oil filler cap, and this is especially true if you only do short drives where the engine doesn't have time to stay hot for long and get rid of some of that moisture that in inside the engine. Oil change is cheap and easy, well, all easy except contorting your arm into a position to turn the oil filter, ha!
If there is any coolant in the oil it will reduce the oil's friction reducing capabilities which could turn a trip to work into a spun bearing.
Condensation under the filler cap can also be caused by and engine that's running under temp too. Might want to check operating temp. If motor doesn't heat up, Condensation doesn't burn off!
 

Latest posts

Members online

Top