Help, cooling system not circulating

[mcs3675]

I just bought a 1999 vx, and the temperature gauge goes from normal to hot, and back! It keeps this up, and i dont know what it could be? Ive replaced the water pump, thermostat, radiator, and all hoses! Still same symptoms, any ideas? Air in system, or is it head gaskets?
Ive awalays wanted a vx, but im regreting this purchase everyday!
Please if anyone has any ideas, and thank you in advance!

Marcus

[Triathlete]

Do you have any antifreeze leaking from anywhere? If not have you checked to see if the radiator is clogged?

[mcs3675]

No leaks, brand new radiator installed today

[PK]

Do you have access to a Scan Gauge or similar to connect to the ECU??
Might be as simple as a faulty gauge, or faulty sender unit??

PK

[Makocross]

You have seemed to have checked all the normal things. Get or buy an infrared thermometer (cheap at harbor freight) and check to see if the temperature really is going up and down. Pick several spots on the engine and radiator to read and see if the temperatures go up and down with your gauge. If the engine temps are staying the same then it is the gauge or sender. If the engine temps are going up and down some one else here will come up with brilliant solution
Mike

[mcs3675]

Scan tool confirmed what the gauge says, its like the thermostat isnt opening, but two faulty stats seems unlikely! Also when the gauge goes to hot i lose heat! The top radiator hose gets hot, top of radiator is hot, bottom hose and core of radiator stays cold

[Makocross]

It seems like there isn't water flow to the radiator. Easiest thing to do is take the thermostat out and see if that makes a difference. If it doesn't then the water pump is bad or there is blockage. Just because it is new parts doesn't mean they can't be bad.
Mike

[mcs3675]

I was thinking of removing the stat tomorrow, but this thing is a pain to work on!

[HeckaTrebeka]

I know that you just changed the thermostat, but it might be a faulty thermostat... I've seen many times in many different cars a freshly installed thermostat fail and give the same symptoms that they had to begin with. Does the temperature change if you're more/less aggressive on the acceleration?

[mcs3675]

It doesnt matter how aggressive it drive, it acts the same, i dont want to drive it to far, im afraid it might get to hot! It stays normal not moving, went from idle to 3k rpm for 45 minutes to night and the temp stayed in the middle! But the radiator and lower hose never warmed up

[VX KAT]

Don't know if you've seen a few of the recent threads on here about temp/overheating issues. Many owners have had problems recently.
Many had done all the things you've done, but still had problem. A few found it was the fan clutch. Also, I recall some saying some of the non-OEM parts were pretty crappy, and they ended up replacing again with OEM.

I know these are long theads, but there's a ton of info in them.
Hope it helps you solve your issue.

http://www.vehicross.info/forums/sho...ight=ron+davis

http://www.vehicross.info/forums/sho...ight=ron+davis

http://www.vehicross.info/forums/sho...ight=ron+davis

http://www.vehicross.info/forums/sho...73&postcount=5

[HeckaTrebeka]

If the hoses are still cold, I would think that's further evidence that the thermostat isn't functioning properly. If one part of your cooling system is cold but the other is hot, then there has to be an obstruction in the cooling system which is the reason I think it's the thermostat.

[Y33TREKker]

Did you try replacing the radiator cap along with all of the other items you mentioned, (or did the new radiator include one?). If the cooling system isn't kept properly pressurized, all of the hot coolant from the system will simply rise quickly to the top of the radiator because it's boiling. A properly functioning radiator cap that keeps the system pressurized will keep all of the coolant in a liquid state though.

It's also important to ensure that no air pockets formed during the coolant filling process.

• Fill the coolant slowly with the engine off
• When the radiator is full, then fill the reservoir to the "Max" mark
• Install and tighten radiator cap
• Idle engine for 2 to 3 minutes
• Stop engine, reopen radiator cap (Carefully!! Hot!!, and refill coolant level if low
• Tighten radiator cap and warm up engine at about 2000 rpm
• Set heater to highest temperature position to allow coolant to circulate into the heater water system
• Make sure thermostat is operating (radiator hoses should get hot)
• Idle engine for 5 minutes, then shut off
• Allow engine to cool, remove radiator cap, and refill coolant level if necessary

I don't know if I've ever seen a fitting on or near the thermostat housings on a VX that allow a person to burp the cooling system when adding coolant (the engine on my car has one), but if a cooling system is filled too quickly and air pockets form in the cooling passages, overheating can occur. That possibility and a faulty radiator cap are my first two guesses anyway.

[bigblock8396375]

I'm having the same problem,but I have excessive pressure in the cooling system. Hoses very hard and pressure is releasing into overflow tank. Hose going to thermostat cold,other hose hot. Temp gauge up and down, heat goes hot and cold. Took out thermostat (was new) ran with no thermostat same issue. Thinking it's a headgasket.

[FenderBender]

I have heard of people installing thermostats upside down. Not sure if one can on a VX? Just throwing it out there.