On a 2000 TJ lately I have been stumped with a couple of issues and
need help on next action from the group...

1. I bought the TJ in September and it was overheating so I changed the
t-stat. Ever since then it has been using about a gallon of 50/50
coolant a month. However there are no external leaks that I can see or
smell. When I changed the coolant and did the t-stat, I noticed some
white crud around the cap and the filler but none has reappeared since
then. Everything I have read points to a head gasket but nothing to
confirm it though;

- Oil cap is clean, and oil level is around normal after over 500 miles
since the change.
- Haven't pressured tested the system, will this tell all?
- Changed the plugs around the same time as the t-stat but they looked
normal or just worn, check these again for a clean plug?

The other issue....

2. After the Jeep is warmed up, typically from highway travel the
pressure gauge at idle with drop and the check gauges light comes on. I
have replaced the sending unit with a new one from the dealer (Mopar)
and changed the oil and filter (10W30) and it still happens.

Don't know if the two issues are related although have seen some other
posts that suggest they may be.

Any thoughts or ideas?

Thanks,

Tom

 

Hi Tom,
Some leaks may be so slight, that you may not be able to see the
vapor, leaving. Look from underneath up at the water pump shaft, at the
weep hole to see if there are any telltale stains. And to put your mind
at ease, find a radiator shop, and they'll be able to test for exhaust
gases.
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/

TJ wrote:
>
> On a 2000 TJ lately I have been stumped with a couple of issues and
> need help on next action from the group...
>
> 1. I bought the TJ in September and it was overheating so I changed the
> t-stat. Ever since then it has been using about a gallon of 50/50
> coolant a month. However there are no external leaks that I can see or
> smell. When I changed the coolant and did the t-stat, I noticed some
> white crud around the cap and the filler but none has reappeared since
> then. Everything I have read points to a head gasket but nothing to
> confirm it though;
>
> - Oil cap is clean, and oil level is around normal after over 500 miles
> since the change.
> - Haven't pressured tested the system, will this tell all?
> - Changed the plugs around the same time as the t-stat but they looked
> normal or just worn, check these again for a clean plug?
>
> The other issue....
>
> 2. After the Jeep is warmed up, typically from highway travel the
> pressure gauge at idle with drop and the check gauges light comes on. I
> have replaced the sending unit with a new one from the dealer (Mopar)
> and changed the oil and filter (10W30) and it still happens.
>
> Don't know if the two issues are related although have seen some other
> posts that suggest they may be.
>
> Any thoughts or ideas?
>
> Thanks,
>
> Tom

 

Hi Tom,
Some leaks may be so slight, that you may not be able to see the
vapor, leaving. Look from underneath up at the water pump shaft, at the
weep hole to see if there are any telltale stains. And to put your mind
at ease, find a radiator shop, and they'll be able to test for exhaust
gases.
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/

TJ wrote:
>
> On a 2000 TJ lately I have been stumped with a couple of issues and
> need help on next action from the group...
>
> 1. I bought the TJ in September and it was overheating so I changed the
> t-stat. Ever since then it has been using about a gallon of 50/50
> coolant a month. However there are no external leaks that I can see or
> smell. When I changed the coolant and did the t-stat, I noticed some
> white crud around the cap and the filler but none has reappeared since
> then. Everything I have read points to a head gasket but nothing to
> confirm it though;
>
> - Oil cap is clean, and oil level is around normal after over 500 miles
> since the change.
> - Haven't pressured tested the system, will this tell all?
> - Changed the plugs around the same time as the t-stat but they looked
> normal or just worn, check these again for a clean plug?
>
> The other issue....
>
> 2. After the Jeep is warmed up, typically from highway travel the
> pressure gauge at idle with drop and the check gauges light comes on. I
> have replaced the sending unit with a new one from the dealer (Mopar)
> and changed the oil and filter (10W30) and it still happens.
>
> Don't know if the two issues are related although have seen some other
> posts that suggest they may be.
>
> Any thoughts or ideas?
>
> Thanks,
>
> Tom

 

Hi Tom,
Some leaks may be so slight, that you may not be able to see the
vapor, leaving. Look from underneath up at the water pump shaft, at the
weep hole to see if there are any telltale stains. And to put your mind
at ease, find a radiator shop, and they'll be able to test for exhaust
gases.
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/

TJ wrote:
>
> On a 2000 TJ lately I have been stumped with a couple of issues and
> need help on next action from the group...
>
> 1. I bought the TJ in September and it was overheating so I changed the
> t-stat. Ever since then it has been using about a gallon of 50/50
> coolant a month. However there are no external leaks that I can see or
> smell. When I changed the coolant and did the t-stat, I noticed some
> white crud around the cap and the filler but none has reappeared since
> then. Everything I have read points to a head gasket but nothing to
> confirm it though;
>
> - Oil cap is clean, and oil level is around normal after over 500 miles
> since the change.
> - Haven't pressured tested the system, will this tell all?
> - Changed the plugs around the same time as the t-stat but they looked
> normal or just worn, check these again for a clean plug?
>
> The other issue....
>
> 2. After the Jeep is warmed up, typically from highway travel the
> pressure gauge at idle with drop and the check gauges light comes on. I
> have replaced the sending unit with a new one from the dealer (Mopar)
> and changed the oil and filter (10W30) and it still happens.
>
> Don't know if the two issues are related although have seen some other
> posts that suggest they may be.
>
> Any thoughts or ideas?
>
> Thanks,
>
> Tom

 

The coolant loss is serious, and if there are no puddles under the vehicle
then you have a blown head gasket or similar problem. You can buy a spark
plug to air compressor adapter, pressurize your cylinders, and watch for
bubbles in the coolant. You can check for a sweetish smell at the exhaust.
If you pressure test the cooling system, this won't necessarily find your
head gasket problem, but it will eliminate the possibility of an external
leak.

Oil pressure drop at idle is expected, but not enough to trigger the check
engine light. You can rent or buy a mechanical pressure gauge to verify
that your dash gauge is or is not the problem. If the gauge is accurate
then you have a mechanical problem, such as a worn oil pump, bad bearings or
stuck pressure relief valve.

Good luck.

Earle

"tk" <thomas_kessler@comcast.net> wrote in message
news:1166115400.816991.237550@16g2000cwy.googlegro ups.com...
> On a 2000 TJ lately I have been stumped with a couple of issues and
> need help on next action from the group...
>
> 1. I bought the TJ in September and it was overheating so I changed the
> t-stat. Ever since then it has been using about a gallon of 50/50
> coolant a month. However there are no external leaks that I can see or
> smell. When I changed the coolant and did the t-stat, I noticed some
> white crud around the cap and the filler but none has reappeared since
> then. Everything I have read points to a head gasket but nothing to
> confirm it though;
>
> - Oil cap is clean, and oil level is around normal after over 500 miles
> since the change.
> - Haven't pressured tested the system, will this tell all?
> - Changed the plugs around the same time as the t-stat but they looked
> normal or just worn, check these again for a clean plug?
>
> The other issue....
>
> 2. After the Jeep is warmed up, typically from highway travel the
> pressure gauge at idle with drop and the check gauges light comes on. I
> have replaced the sending unit with a new one from the dealer (Mopar)
> and changed the oil and filter (10W30) and it still happens.
>
> Don't know if the two issues are related although have seen some other
> posts that suggest they may be.
>
> Any thoughts or ideas?
>
> Thanks,
>
> Tom
>

 

The coolant loss is serious, and if there are no puddles under the vehicle
then you have a blown head gasket or similar problem. You can buy a spark
plug to air compressor adapter, pressurize your cylinders, and watch for
bubbles in the coolant. You can check for a sweetish smell at the exhaust.
If you pressure test the cooling system, this won't necessarily find your
head gasket problem, but it will eliminate the possibility of an external
leak.

Oil pressure drop at idle is expected, but not enough to trigger the check
engine light. You can rent or buy a mechanical pressure gauge to verify
that your dash gauge is or is not the problem. If the gauge is accurate
then you have a mechanical problem, such as a worn oil pump, bad bearings or
stuck pressure relief valve.

Good luck.

Earle

"tk" <thomas_kessler@comcast.net> wrote in message
news:1166115400.816991.237550@16g2000cwy.googlegro ups.com...
> On a 2000 TJ lately I have been stumped with a couple of issues and
> need help on next action from the group...
>
> 1. I bought the TJ in September and it was overheating so I changed the
> t-stat. Ever since then it has been using about a gallon of 50/50
> coolant a month. However there are no external leaks that I can see or
> smell. When I changed the coolant and did the t-stat, I noticed some
> white crud around the cap and the filler but none has reappeared since
> then. Everything I have read points to a head gasket but nothing to
> confirm it though;
>
> - Oil cap is clean, and oil level is around normal after over 500 miles
> since the change.
> - Haven't pressured tested the system, will this tell all?
> - Changed the plugs around the same time as the t-stat but they looked
> normal or just worn, check these again for a clean plug?
>
> The other issue....
>
> 2. After the Jeep is warmed up, typically from highway travel the
> pressure gauge at idle with drop and the check gauges light comes on. I
> have replaced the sending unit with a new one from the dealer (Mopar)
> and changed the oil and filter (10W30) and it still happens.
>
> Don't know if the two issues are related although have seen some other
> posts that suggest they may be.
>
> Any thoughts or ideas?
>
> Thanks,
>
> Tom
>

 

The coolant loss is serious, and if there are no puddles under the vehicle
then you have a blown head gasket or similar problem. You can buy a spark
plug to air compressor adapter, pressurize your cylinders, and watch for
bubbles in the coolant. You can check for a sweetish smell at the exhaust.
If you pressure test the cooling system, this won't necessarily find your
head gasket problem, but it will eliminate the possibility of an external
leak.

Oil pressure drop at idle is expected, but not enough to trigger the check
engine light. You can rent or buy a mechanical pressure gauge to verify
that your dash gauge is or is not the problem. If the gauge is accurate
then you have a mechanical problem, such as a worn oil pump, bad bearings or
stuck pressure relief valve.

Good luck.

Earle

"tk" <thomas_kessler@comcast.net> wrote in message
news:1166115400.816991.237550@16g2000cwy.googlegro ups.com...
> On a 2000 TJ lately I have been stumped with a couple of issues and
> need help on next action from the group...
>
> 1. I bought the TJ in September and it was overheating so I changed the
> t-stat. Ever since then it has been using about a gallon of 50/50
> coolant a month. However there are no external leaks that I can see or
> smell. When I changed the coolant and did the t-stat, I noticed some
> white crud around the cap and the filler but none has reappeared since
> then. Everything I have read points to a head gasket but nothing to
> confirm it though;
>
> - Oil cap is clean, and oil level is around normal after over 500 miles
> since the change.
> - Haven't pressured tested the system, will this tell all?
> - Changed the plugs around the same time as the t-stat but they looked
> normal or just worn, check these again for a clean plug?
>
> The other issue....
>
> 2. After the Jeep is warmed up, typically from highway travel the
> pressure gauge at idle with drop and the check gauges light comes on. I
> have replaced the sending unit with a new one from the dealer (Mopar)
> and changed the oil and filter (10W30) and it still happens.
>
> Don't know if the two issues are related although have seen some other
> posts that suggest they may be.
>
> Any thoughts or ideas?
>
> Thanks,
>
> Tom
>

 

I agree with Earl. The coolant issue is serious; on gallon per month is
very serious. It's going somewhere, and you must find out where. I've
seen test strips that when dipped in the coolant, indicate the presense
of hydrocarbons, a telltale sign of a blown head gasket. Doing a
leakdown test will usually pinpoint this as well; a drop in pressure
followed by a visual examination into each spark plug hole will tell you
where the head gasket has been breached. Either way, you should repair
the problem or have a mechanic do the work for you. This is unusual for
a 4.0 engine.

The 'check guages' lamp usually indicates a faulty dash guage. They are
expensive to replace, but I would do it regardless of cost. You can
first check for proper oil pressure by hooking up a mechanical oil
pressure guage and comparing the readings.

If this were me, I'd just find a very good mechanic and have everything
fixed all at once. You're probably looking at 5-$700 for everything,
with most being labor. You bought a very good quality truck: it's worth
the bucks to have it fixed right.

 

I agree with Earl. The coolant issue is serious; on gallon per month is
very serious. It's going somewhere, and you must find out where. I've
seen test strips that when dipped in the coolant, indicate the presense
of hydrocarbons, a telltale sign of a blown head gasket. Doing a
leakdown test will usually pinpoint this as well; a drop in pressure
followed by a visual examination into each spark plug hole will tell you
where the head gasket has been breached. Either way, you should repair
the problem or have a mechanic do the work for you. This is unusual for
a 4.0 engine.

The 'check guages' lamp usually indicates a faulty dash guage. They are
expensive to replace, but I would do it regardless of cost. You can
first check for proper oil pressure by hooking up a mechanical oil
pressure guage and comparing the readings.

If this were me, I'd just find a very good mechanic and have everything
fixed all at once. You're probably looking at 5-$700 for everything,
with most being labor. You bought a very good quality truck: it's worth
the bucks to have it fixed right.

 

I agree with Earl. The coolant issue is serious; on gallon per month is
very serious. It's going somewhere, and you must find out where. I've
seen test strips that when dipped in the coolant, indicate the presense
of hydrocarbons, a telltale sign of a blown head gasket. Doing a
leakdown test will usually pinpoint this as well; a drop in pressure
followed by a visual examination into each spark plug hole will tell you
where the head gasket has been breached. Either way, you should repair
the problem or have a mechanic do the work for you. This is unusual for
a 4.0 engine.

The 'check guages' lamp usually indicates a faulty dash guage. They are
expensive to replace, but I would do it regardless of cost. You can
first check for proper oil pressure by hooking up a mechanical oil
pressure guage and comparing the readings.

If this were me, I'd just find a very good mechanic and have everything
fixed all at once. You're probably looking at 5-$700 for everything,
with most being labor. You bought a very good quality truck: it's worth
the bucks to have it fixed right.