[callpal411]

Hi My 99 4.6hse keeps blowing the heater return hose, I replaced one, it worked for a week. then the temp started going up, in a couple of minutes it would go back to normal, then after few minutes it would go up again. It did that for a few times and then the heater return hose blew up.
The thermostat was changed about six month ago.
Any ideas?
Here is what else is going on with it, I have the book mark display and am not getting any cold or hot air on the driver side and I believe I need to change the heater O ring, occasionally I would get some cold water/coolant? on my right foot which is on the gas pedal ( I am in the States ).
Any help would be much appreciated. The mileage on the vehicle is 100,400 miles.
Thanks in advance

 

[viperover]

When you mention blowing the pipe would that be bursting or comming off the aaly pipe.

Fluctuating temp gauge is not a good sign indeed but firstly I would replace the sender unit before I possibly mention the dreaded head gasket issue, when thermostat was replaced previously did it over heat then.

Sounds like you have a blen motor failure on the climate control system..

 

[RRToadHall]

LIquid on your right foot in the states would be A/C condensation not draining and would have nothing to do with heater rings.

 

[callpal411]

When you mention blowing the pipe would that be bursting or comming off the aaly pipe.

Fluctuating temp gauge is not a good sign indeed but firstly I would replace the sender unit before I possibly mention the dreaded head gasket issue, when thermostat was replaced previously did it over heat then.

Sounds like you have a blen motor failure on the climate control system..

The pipe is bursting, what is a sender unit?

 

[viperover]

Sender unit is a sensor that measures, in this case the temp of the coolant, it sends information to your dash cluster informing you via a gauge how hot the coolant is.

you say pipe is bursting, unless its a bad batch of pipes which I doubt seems you may a problem

 

[RRToadHall]

Pipes or hoses? The hose is the flexible thing that slips over the pipe.. the hard thing. I seriously doubt our systems could produce enough pressure to blow pipes. If you are blowing hoses as I would expect, are they LR replacements, or a generic length you have put in?

 

[diff]

If you had fluctuations it also sounds like system had air in it that was not bled. You should have continuous water with bubles pouring in to your resevoir tank. This is from the small hose attached to top of rad tank. As a further note to rr's question is the clamp used possibly cutting into the hose thereby promoting a tear.

 

[Jos Geuze]

Hi

There shouldn't be much pressure in the coolingsystem. You should be able to squeeze the hoses easily with the engine running. If you open the cap from the reservior there should only be a puff of air coming out.

Check these things and if there is excessive pressure then there is most likely a leak from your combustion chambers into the coolingwater circuit. To make sure of this go to a garage and do a sniffer test of the coolant to check for combustion gas residue in the water.

If this second test is positive then you have to rectify the cause whether it is a blown head gasket or porous engine block.

Regards

Jos

 

[viperover]

Removing spark plugs can most of the time show which cylinder is problematic by looking a lot cleaner, like new compared to the rest of them

 

[Dan_UK_1984]

If the temperature is fluctuating then perhaps the system needs bleeding? The P38 can be a bit of a pain to bleed, basically run it for 10 mins with the cap off whilst squeezing and letting go of the top rad hose to push the bubbles through to the expansion tank. If not bled properly you will develop pockets of super heated coolant (steam) if there is an air lock in the system as the coolant is allowed to expand and turn to gas, this is self perpetuating as there is then less coolant to cool the engine. First of all try bleeding the system.

The system shouldn't be able to get to the sort of pressure to blow a hose off as there is a pressure release valve in the expansion tank cap (has this been replaced before you start panicking?) Also I'm guessing you put the hose on nice and tight?


Dan