• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Q's about a no start MJ

OkieXJ

OkieXJ

NAXJA Forum User
NAXJA Member
Location
Muskogee, OK
I have an opportunity to pick up a CHEAP MJ, '87 2wd 4spd manual. The seller said it got hot and blew a radiator hose, engine will turn over but not start, says it needs a new head gasket. I'd like to buy it and get it running again. Are there any quick and easy ways to tell if the engine has been trashed and requires a rebuild? I don't mind replacing a head gasket but I don't think I want to tackle a complete engine rebuild. Thanks for any info or comments.
 
Do a compression check. Weak numbers on adjacent cylinders would be suspect for a head gasket.

Check oil and coolant. Brown and/or milky oil = bad. Brown or oily coolant = bad.

Does the owner belive that it needs a head gasket because it was over pressurized and therefore blew a hose or did he just flog the crap out it and it got too hot?
 
I'd have to do the compression check at the sellers place and I don't think I'll have time. Good question about the pressure. I think he said that because it blew a hose, I get the impression he's not the type to flog the crap out of it but who knows. I'll definitely check the oil.

While reading about how to perform a compression test, everyone says you have to get it up to operating temperature. How do you do that on something that doesn't run? Or do you just ignore that and check it while its cold?
 
OkieXJ said:
While reading about how to perform a compression test, everyone says you have to get it up to operating temperature. How do you do that on something that doesn't run? Or do you just ignore that and check it while its cold?
Click to expand...

I do compression tests both hot and cold. Comparing hot and cold readings sometimes helps troubleshoot.
For this situation cold should tell you alot.
OR
If CHEAP is cheap enough just take it home and play with it.
 
Yes, just do it cold.

Do a dry test on all cylinders first, then shoot a little oil into each cylinder and repeat the test "wet". If you see a big change between dry and wet the rings are worn.
 
I'll take my compression Gage along. Is it common for an overheated engine to wreck bearings and pistons? I know it is common to warps the head and blows out the gasket.
 
Usually the head gasket/head goes before the oil gets cooked enough to damage bearings from lack of lubrication, HOWEVER, if coolant mixed with the oil is left in the crankcase, or the engine is run much with contaminated oil, that is pretty rough on the bearings.
 
So if the head gasket blew out, could that account for the no start problem? If I replace the head gasket and the head isn't warped I suppose it should start if that was the problem. I'm going to go look at the MJ tonight.
 
how much does he want for it? If it's cheap enough just buy it and figure out what's wrong with it later. A motor won't run you more than a few hundred bucks, I can pick one up at my local you-pull-it for $160, $260 if I have them pull it.
 
$300 is the asking price.
87Comanche.jpg
 
Do it. At that price you cannot lose. Drag the sucker home and figure it out later, never look back!

(unless it's literally rusting in half but it doesn't seem to be)
 
kastein said:
Do it. At that price you cannot lose. Drag the sucker home and figure it out later, never look back!

(unless it's literally rusting in half but it doesn't seem to be)
Click to expand...

Check! I'll definitely make sure it isn't rusted too bad. I don't want to get into patching frame rails, floor panels, etc.
 
Didn't look too rusty so I brought this home yesterday.
0cd40384.jpg

Unfortunately crummy weather has kept me from investigating the head gasket. The body is more rough than the pictures show but a new front clip and fender should fix that right up. Getting this thing running will be priority #1 before any body work gets done.
 
kastein said:
how much does he want for it? If it's cheap enough just buy it and figure out what's wrong with it later. A motor won't run you more than a few hundred bucks, I can pick one up at my local you-pull-it for $160, $260 if I have them pull it.
Click to expand...

I pulled the head off the truck and there is about 0.020" clearance between the straight edge and the wall between cylinders #2 and #3. I'm going to check new engine prices and call the local machine shop to get a quote in having this thing resurfaced. I have a new head gasket and I'm considering putting the engine back together with it to see if I can get it running for the time being though. If I could pick up an engine for $160 I do that in an instant but we'll see.

Anybody have a ballpark guess as to what a machine shop would charge to resurface the head?
 
You must log in or register to reply here.

Similar threads

T
Temp gauge stuck ?
Replies
6
Views
2K
Tonyt22
T
M
Coolant Temp Sensor
Replies
3
Views
2K
Unclewolverine
U
Ecomike
87 Renix XJ No fuel, No brake lights, cranks fine
2
Replies
27
Views
855
Anak
Anak
S
No Start No Bus
Replies
16
Views
3K
Rob Mayercik
R
N
New Engine is Hard to Start
Replies
0
Views
33
NGThomas
N
Back
Top