absolutley no heat...

[madmazda]

fan motor works... no heat out of either front heat or rear heat..... heat was working a while ago now nothing.... the temp guage on eingne is at cold.... could this be as simple as changing the thermostat ??? any sugestions.....

[mararmeisto]

Do you have heat once the engine is warmed up?

Does the dash gauge register heat after the engine warms up?

Could be your thermostat... could be your temperature sensor...

[Artacoma]

I only have heat at increased rpm , not much tho, nothing at idle. Met a few l400's at the meet on Friday with the same. My l300 had loads of heat.
Right now I suspect a clogged heater core as mine and most others have new rads installed at importation it makes sense that the heater core would be crappy as well.
I'm going to be doing some more poking behind my dash this week , I'll post here if I find anything.

[jessef]

thermostat

Its not opening allowing hot coolant to pass through the heater core.

[Artacoma]

If the thermostat wasn't opening wouldn't van be overheating?

[Mr. Flibble]

Thermostat is the first thing to look at, as well as coolant level. Next is restrictions in radiators. I would bet thermostat.

[mrdueck]

If the thermostat wasn't opening wouldn't van be overheating?

Yes, but 99% of the time when a thermostat fails, it stays open. Thus you won't get heat unless you really work the motor hard.
Rudy

[madmazda]

thanks for the replies the temp guage is at cold.... but has been there for a while and still blow heat.... except for now. went for a long drive today still no heat what so ever... will get new thermostat soon now that its going to warm all heater hoses are good n warm loostned up air bleed valve a bit of air came out with coolant so hope it is the thermostat

[Mr. Flibble]

How is your coolant level? Have you checked? Look at the colour of your oil. If creamy, or if you see oil in your coolant you have a blown head gasket and should not drive.

[thelazygreenfox]

Guys I'm having the same problem. It was damn cold with my tailgate up Sat morning driving to the Harrison fishing for coho. My boat fits in the back but only with the tailgate up a bit. The fan only blew warm air.

I'm replacing my thermostat tomorrow morning.

Wayne
TLGF

[jwfchase]

After a lot of money and frustration having most of my cooling system serviced, it came down to this realtively simple fix: Coolant flush. Not coolant change, as in draining coolant and adding more, but the pressurised full system flush. Even though my coolant was changed a few months ago, when I took it in for an oil change last week, the coolant came out looking dirty. Went for their system flush- lots of crap came out, and we now have hot air from the vents!

[madmazda]

Well thermostat changed as well as temp sensor for the guage and oil psi sensor fixed ( was pissing oil out of threads thing was hardly threaded in 3 threads...) so put coolent in started the ole girl up let run for a while.... and a bit of heat from vents.... way more that sunday... so i'm thinking just run for a while and let the air get out.... if nothing then a psi system flush..... would any one know where to get this done ??? in calgary of course...

[Mr. Flibble]

Well thermostat changed as well as temp sensor for the guage and oil psi sensor fixed ( was pissing oil out of threads thing was hardly threaded in 3 threads...) so put coolent in started the ole girl up let run for a while.... and a bit of heat from vents.... way more that sunday... so i'm thinking just run for a while and let the air get out.... if nothing then a psi system flush..... would any one know where to get this done ??? in calgary of course...

You can get a coolant flush done almost anywhere that has a competent mechanic. I think you can even get them at Jiffy Lube or the equivalents. If you have air in your system though, it would also cause the symptoms you have. it is also not great for your engine either.

[Artacoma]

Put in a new thermostat today .... No difference .... Hottest air from the vents is 19 c and ats with a warm engine. The coolant looks new. Waiting for quotes on new heater core.

[thelazygreenfox]

I changed my thermostat, flushed both heater cores and the radiator. The antifreeze was quite rusty so I changed the ratio to 80/20 from 50/50. Hopefully it isn't as rusty next time.

The antifreeze was drained and dropped it off at Canadian Tire.

With a garden hose I flushed from the top (air) bleed under the hood to the outlet of the rear heater core under the van. Next the radiator was flushed from the top to the bottom outlet hose. No solid material came out from either flush, just very rusty water.

With the thermostat changed I refilled and tested the outlet heat. Unfortunately the outside temp was +5 deg C. but I'll retest temp the next cold day. With the heat set at max and warm air icon setting on, the dash and rear vents registered over 100 deg F.

Don't know what made the difference but I have lots of heat now.

Good luck
Wayne
TLGF