Go Back   Infamous Nissan - Hardbody / Frontier Forums > Tech Area > Engine and Drivetrain

Reply
 
Thread Tools Display Modes
Old 04-26-2017, 11:45 PM   #1
chvbob
 
Join Date: Jan 2013
Location: Washington
Posts: 10
Vehicle: 1991 Nissan d21
Thanks: 0
Thanked 0 Times in 0 Posts
Default overheating

I know this has been covered, and I have read most of the threads. I have a 1991 D21 2.4 non A/C that I have been fighting with for a month, and a half. It started to heat up just about to the high mark, but did not boil out. I will tell you what I have done. The pump is about 6 months old, but I pulled it, and checked to make sure the impeller was tight on the shaft, and everything looked good. I changed out the thermostat with a Stant, and no help. I read the threads, and got an OEM stat from the dealer. No help there either. I tested both t stats in boiling water, and they both opened within 5 degrees of each other at 170 degrees. I flushed the system good until I was running clear water. I removed the thermostat, and ran it. It took longer to heat up naturally, but it still heated. I have burped this system for hours each time. With the exception of one time, it has not boiled over. I cut the center out of and old tstat, and installed it, hoping it would slow the flow down. Same thing. I broke down and bought a new radiator, and a new temp sending unit. After installing with the tstat, and burping again for 2 1/2 hours, it still does the same thing. Not as bad, but still hot. It won't heat up when idling, but about 10 miles on the road, and it is up to the hot level. At the same time that it starts to heat, I lose the heater, indicating to me, another air lock. Back to the burping. This time I removed the temp sender, and filled it until water was running free out of the hole, and installed it while the water was running. Still the same. the other thing is, when it does this, it loses about a gallon of water. While idling, cant see any leakes, but it isn't hot. No oil in the water, or water in the oil. Pressure tested it at 16 lbs, and no leaks. I did a compression check to make sure, and I am running 130 lbs across all 4. Don't know about the fan clutch as there isn't any play that I can feel, and it does have some restriction on turning it. Starting to think it is ready for a shot gun. Any help would be greatly appreciated.
chvbob is offline   Reply With Quote
Old 04-27-2017, 02:12 AM   #2
cadillacdude1975
The Gear Jammer
 
cadillacdude1975's Avatar
 
Join Date: Apr 2013
Location: Chattanooga, TN
Age: 46
Posts: 8,355
Vehicle: 87 D21 SE KC V6 2wd 5sp & 86.5 V6 SE auto
Thanks: 294
Thanked 924 Times in 856 Posts
Default

have you verified the temp with a real thermometer? could be a cracked head. or a temp gauge that is lying. just thinking off the top of my head you know...............
__________________
"Im officially lost" - wildbill
cadillacdude1975 is offline   Reply With Quote
Old 04-27-2017, 04:51 AM   #3
Green-meanie187
The Rakkasan
 
Green-meanie187's Avatar
 
Join Date: Feb 2017
Location: Florida
Posts: 272
Vehicle: 96 Nissan XE 2.4
Thanks: 2
Thanked 22 Times in 18 Posts
Default

Doesn't heat up at all? Sounds like a head gasket actually. If you can manage to get your hands on it, get a combustion leak tester. The fluid is one color, and if you have exhaust leaking in your cooling system, it will change color.

If it's the possibility of a cracked head, pull the head and take it to a machine shop. They'll find your problem.
__________________
" I am the punishment of God. If you had not committed great sins, God would not have sent a punishment like me upon you" -Gengis Khan
Green-meanie187 is offline   Reply With Quote
Old 04-27-2017, 11:03 AM   #4
LugNut1990
 
LugNut1990's Avatar
 
Join Date: Jul 2015
Location: N.E. Kansas
Posts: 318
Vehicle: 1990 Nissan Hardbody
Thanks: 0
Thanked 22 Times in 22 Posts
Default

AutoZone loans out a tool called a "block tester" (kit). Be sure to get its fluid too; they may charge for it. Worked well for me in verifying a cracked head on another brand vehicle.
__________________
Original owner
1990 Nissan Hardbody, Aztec Red
Standard cab, 4x4, KA24E, 5-speed
Intentionally near-stock
Mods: Second OEM horn, stereo/speakers/sub,
mud and snow tires, HD trailer hitch (cat 3+),
liquid bed liner, G1W dashcam
Definitely not for sale!
LugNut1990 is offline   Reply With Quote
Old 04-27-2017, 04:44 PM   #5
Reserector
the Flaming Marshmallow
 
Reserector's Avatar
 
Join Date: Oct 2015
Location: Laurel, MS
Posts: 1,371
Vehicle: Nissan HB KC 4x4
Thanks: 10
Thanked 306 Times in 247 Posts
Default

Sounds like it is sucking water into the combustion chamber/s.
It could be sucking water through the head gasket OR the intake. (There are a few places where coolant could leak in to the intake manifold.) It could also be a crack somewhere.

Does it start on two or three cylinders, and then clear up? That would be a clue that water is seeping in after it is shut off.

If coolant is not being pushed back into the overflow, it is being sucked into the engine.
Does your overflow level ever change? If it is filling up, but not drawing back into the radiator after cooling, you have an air leak in your overflow system.
Reserector is offline   Reply With Quote
Old 04-27-2017, 05:11 PM   #6
SBJ
Total Buzzkill
 
Join Date: Nov 2016
Location: OR
Posts: 1,412
Vehicle: '90 D21 4cyl 5spd 2wd
Thanks: 156
Thanked 153 Times in 141 Posts
Default

To add to what reserector is saying are any of your spark plugs unusually clean? That's a good indicator there's coolant getting into the combustion chamber.
SBJ is offline   Reply With Quote
Old 04-27-2017, 07:21 PM   #7
chvbob
 
Join Date: Jan 2013
Location: Washington
Posts: 10
Vehicle: 1991 Nissan d21
Thanks: 0
Thanked 0 Times in 0 Posts
Default

I did check the plugs when I did the compression check. The idea of a cracked head doesn't make sense to me. I guess I could have a crack somewhere that doesn't affect anything other than the coolant passages. Why would the pressure test not show a leak? I made my own exhaust gas tester for the radiator. Used the proper fluid, and it didn't turn color. Maybe I will go get the real thing and give it a go. It does seem to be sucking air back into the system after it is burped.
chvbob is offline   Reply With Quote
Old 04-27-2017, 07:41 PM   #8
YEPEE
 
Join Date: Mar 2013
Location: Phoenix
Posts: 1,553
Vehicle: 86.5 HB, 02 Sentra Spec-V
Thanks: 149
Thanked 227 Times in 200 Posts
Default

stupid question, were does the needle normally point? cold side, half way etc ?? is this truck new to you? some of these trucks the needle does read a little high, that is way I am asking... everyone on here probably has a different "normal" reading...
YEPEE is offline   Reply With Quote
Old 04-28-2017, 12:01 AM   #9
Green-meanie187
The Rakkasan
 
Green-meanie187's Avatar
 
Join Date: Feb 2017
Location: Florida
Posts: 272
Vehicle: 96 Nissan XE 2.4
Thanks: 2
Thanked 22 Times in 18 Posts
Default

Quote:
Originally Posted by chvbob View Post
I did check the plugs when I did the compression check. The idea of a cracked head doesn't make sense to me. I guess I could have a crack somewhere that doesn't affect anything other than the coolant passages. Why would the pressure test not show a leak? I made my own exhaust gas tester for the radiator. Used the proper fluid, and it didn't turn color. Maybe I will go get the real thing and give it a go. It does seem to be sucking air back into the system after it is burped.
Yea.. go get the real deal. You're either dealing with upper and lower hoses, or heater hoses. I'd also check the coolant temp sensor. If it's not reading right, it will throw everything way off. Infact, just replace it actually.
__________________
" I am the punishment of God. If you had not committed great sins, God would not have sent a punishment like me upon you" -Gengis Khan
Green-meanie187 is offline   Reply With Quote
Old 04-28-2017, 04:27 PM   #10
chvbob
 
Join Date: Jan 2013
Location: Washington
Posts: 10
Vehicle: 1991 Nissan d21
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Ok folks. I went and got the block tester. Tried three times, and it would not change color. Every time I sucked the fluid level down to the core, and tested, the coolant would eventually build up to the tool causing it to need to be redone. When I removed the tool the third time, it had a lot of pressure in the system. I did notice water at my tailpipe, DUH should have noticed that earlier. Pulled the plugs again to isolate the bad cyl., they all looked good. I knew then that I probably had a crack that was opening up when the engine temp came up. Don't know why I didn't notice any white smoke, but it is the only thing that made sense. I was out of money, so I can't tear it down right now, so I bought some Blue Devil sealer. Removed my t stat so it could run for an hour or so. Put the fluid in, toped it off, and started. Ran it for an hour and one half. Got warm, but didn't overheat. The water coming out of the tailpipe slowed almost to a stop, and the temp actually came down some. Let it sit all night, and will check coolant level this morning, and test drive it today. I will report back on the experience. Thanks for all the ideas. This problem is one that stumped me longer than anything since 1968. Maybe I am just getting old, and forgot some simple things.
chvbob is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 05:35 PM.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.