4.0L overheating
 

Hi,

I'm having a weird overheating problem and I need a little help. First,
the details. I have an 87 YJ and I just finished putting a 4.0L into it
from a 96 ZJ donor. The swap went well except that the motor "appears"
to be overheating. I am running the new engine with my original radiator
(never had heat problems before).

After running it for a few minutes the temp gauge starts to climb up
towards red line. However, the engine shows no physical signs of
overheating. I can touch the head (front and back) and it's not very hot
at all. Also, I can open the radiator cap and actually stick my finger
in the coolant for a second or so. The is all while the temp gauge is
reading about 210-220.

I thought perhaps the coolant wasn't flowing, but I felt the large hose
on top and the two hoses to and from the heater core. All three were
pretty warm. The bottom radiator hose was warm too, but not as warm as
the top hose (I think). Also the radiator itself was pretty warm
indicating at least some circulation.

I've put the front wheels on ramps in case I had an air bubble in the
pump, but it didn't help any. Also, I looked in the radiator while the
engine was running, and couldn't really see fluid flowing. Should I be
able to see this?

Final notes - I have a bit of belt squeal at initial startup, but all
the pullies are moving. Also, keep in mind that all this is happening in
15* degree weather.

What do you guys think? Any ideas? Your help is greatly appreciated.

Ryan

Re: 4.0L overheating
 

Ryan did pass the time by typing:
> Hi,

Hello..

Wonder if the temp sensor is the same between the older and newer
engine. If its curve is different that might be what is throwing
your temp gauge off. Does the old temp sender fit in the new engine?

You could check by seeing what a couple of known resistors read
vs what the sensor shows.
http://members.cox.net/wilsond/Fixes...tml#tempmatrix


--
-- DougW -- 93 ZJ 4.0 http://members.cox.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors

Re: 4.0L overheating
 

Ryan did pass the time by typing:
> Hi,

Hello..

Wonder if the temp sensor is the same between the older and newer
engine. If its curve is different that might be what is throwing
your temp gauge off. Does the old temp sender fit in the new engine?

You could check by seeing what a couple of known resistors read
vs what the sensor shows.
http://members.cox.net/wilsond/Fixes...tml#tempmatrix


--
-- DougW -- 93 ZJ 4.0 http://members.cox.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors

Re: 4.0L overheating
 

Ryan did pass the time by typing:
> Hi,

Hello..

Wonder if the temp sensor is the same between the older and newer
engine. If its curve is different that might be what is throwing
your temp gauge off. Does the old temp sender fit in the new engine?

You could check by seeing what a couple of known resistors read
vs what the sensor shows.
http://members.cox.net/wilsond/Fixes...tml#tempmatrix


--
-- DougW -- 93 ZJ 4.0 http://members.cox.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors

Re: 4.0L overheating
 

Roughly 1/24/04 16:35, DougW's monkeys randomly typed:

> Ryan did pass the time by typing:
>> Hi,
>
> Hello..
>
> Wonder if the temp sensor is the same between the older and newer
> engine. If its curve is different that might be what is throwing
> your temp gauge off. Does the old temp sender fit in the new engine?
>
> You could check by seeing what a couple of known resistors read
> vs what the sensor shows.
> http://members.cox.net/wilsond/Fixes...tml#tempmatrix
>
>
? Serpentine belt turning the water pump bassackwards ?

--
Now that Spirit Rover has confirmed the presence of weapons of
mass destruction on Mars, we are preparing to invade...

Re: 4.0L overheating
 

Roughly 1/24/04 16:35, DougW's monkeys randomly typed:

> Ryan did pass the time by typing:
>> Hi,
>
> Hello..
>
> Wonder if the temp sensor is the same between the older and newer
> engine. If its curve is different that might be what is throwing
> your temp gauge off. Does the old temp sender fit in the new engine?
>
> You could check by seeing what a couple of known resistors read
> vs what the sensor shows.
> http://members.cox.net/wilsond/Fixes...tml#tempmatrix
>
>
? Serpentine belt turning the water pump bassackwards ?

--
Now that Spirit Rover has confirmed the presence of weapons of
mass destruction on Mars, we are preparing to invade...

Re: 4.0L overheating
 

Roughly 1/24/04 16:35, DougW's monkeys randomly typed:

> Ryan did pass the time by typing:
>> Hi,
>
> Hello..
>
> Wonder if the temp sensor is the same between the older and newer
> engine. If its curve is different that might be what is throwing
> your temp gauge off. Does the old temp sender fit in the new engine?
>
> You could check by seeing what a couple of known resistors read
> vs what the sensor shows.
> http://members.cox.net/wilsond/Fixes...tml#tempmatrix
>
>
? Serpentine belt turning the water pump bassackwards ?

--
Now that Spirit Rover has confirmed the presence of weapons of
mass destruction on Mars, we are preparing to invade...

Re: 4.0L overheating
 

Actually, I just got back from Advance Auto and I may have found the
problem. It's related to your suggestion.

When I put the engine in it didn't have a temp sender, so I went to
AutoZone and bought one for a 96 ZJ. However, I was at Advance Auto 15
minutes ago and just for kicks asked how much a temp sender was. They
had two different models - one was if you had a warning light and the
other was if you had a gauge!! I'm thinking that maybe they are
calibrated differently and that AutoZone may have given me the wrong
one. I hope it's that simple.

Now that I think about it, I should have mentioned that my computer and
gauges are from a 93 Wrangler (yes, very Frankenstein I know). Should I
have bought the temp sender for a 96 ZJ (what the engine is from) or a
93 YJ (what the comp/gauges are from)?

Also, why is Advance Auto listing two different temp senders for a 96
ZJ? Is there another sender besides the one on the head by the firewall
that I don't know about?

Thanks for your help!

Ryan


DougW wrote:
> Ryan did pass the time by typing:
>
>>Hi,
>
>
> Hello..
>
> Wonder if the temp sensor is the same between the older and newer
> engine. If its curve is different that might be what is throwing
> your temp gauge off. Does the old temp sender fit in the new engine?
>
> You could check by seeing what a couple of known resistors read
> vs what the sensor shows.
> http://members.cox.net/wilsond/Fixes...tml#tempmatrix
>
>

Re: 4.0L overheating
 

Actually, I just got back from Advance Auto and I may have found the
problem. It's related to your suggestion.

When I put the engine in it didn't have a temp sender, so I went to
AutoZone and bought one for a 96 ZJ. However, I was at Advance Auto 15
minutes ago and just for kicks asked how much a temp sender was. They
had two different models - one was if you had a warning light and the
other was if you had a gauge!! I'm thinking that maybe they are
calibrated differently and that AutoZone may have given me the wrong
one. I hope it's that simple.

Now that I think about it, I should have mentioned that my computer and
gauges are from a 93 Wrangler (yes, very Frankenstein I know). Should I
have bought the temp sender for a 96 ZJ (what the engine is from) or a
93 YJ (what the comp/gauges are from)?

Also, why is Advance Auto listing two different temp senders for a 96
ZJ? Is there another sender besides the one on the head by the firewall
that I don't know about?

Thanks for your help!

Ryan


DougW wrote:
> Ryan did pass the time by typing:
>
>>Hi,
>
>
> Hello..
>
> Wonder if the temp sensor is the same between the older and newer
> engine. If its curve is different that might be what is throwing
> your temp gauge off. Does the old temp sender fit in the new engine?
>
> You could check by seeing what a couple of known resistors read
> vs what the sensor shows.
> http://members.cox.net/wilsond/Fixes...tml#tempmatrix
>
>

Re: 4.0L overheating
 

Actually, I just got back from Advance Auto and I may have found the
problem. It's related to your suggestion.

When I put the engine in it didn't have a temp sender, so I went to
AutoZone and bought one for a 96 ZJ. However, I was at Advance Auto 15
minutes ago and just for kicks asked how much a temp sender was. They
had two different models - one was if you had a warning light and the
other was if you had a gauge!! I'm thinking that maybe they are
calibrated differently and that AutoZone may have given me the wrong
one. I hope it's that simple.

Now that I think about it, I should have mentioned that my computer and
gauges are from a 93 Wrangler (yes, very Frankenstein I know). Should I
have bought the temp sender for a 96 ZJ (what the engine is from) or a
93 YJ (what the comp/gauges are from)?

Also, why is Advance Auto listing two different temp senders for a 96
ZJ? Is there another sender besides the one on the head by the firewall
that I don't know about?

Thanks for your help!

Ryan


DougW wrote:
> Ryan did pass the time by typing:
>
>>Hi,
>
>
> Hello..
>
> Wonder if the temp sensor is the same between the older and newer
> engine. If its curve is different that might be what is throwing
> your temp gauge off. Does the old temp sender fit in the new engine?
>
> You could check by seeing what a couple of known resistors read
> vs what the sensor shows.
> http://members.cox.net/wilsond/Fixes...tml#tempmatrix
>
>