Help With Thermostat Please!!!

[mattp]

HI guys, I just need some quick help, I just changed my thermostat, easy as anything, BUT the one I got from Ford and the one I took out of my car are different...

Just want to see if anyone has an explanation for this, and does it make any difference? I thought I might as well put the new one in for now, but don't want to go driving if it's going to hurt the car.

Oh, just to help things, as I was looking at the one I took out I dropped it and it's bent, so I can't put it back in.

The bit circled in red is the difference anyway, this bit isn't there on the new one, it's just got the copper looking ball with nothing sticking out of it.

Thanks heaps in advance for any help / advice !!

Matt.

[mattp]

It's a series 1 I6 by the way

[JC]

Yep, just a different design to achieve the same thing. I've got the "short" one in my AU2 (I6) and it works fine.

[mattp]

Thanks JC, I thought it would just be a variant but wanted to make sure I wasn't given the wrong one. Cheers!

[NeishaXR8_347]

What that thing does that is missing is block off the pipe that goes to the water pump, in not having this it will take it a bit longer to heat up.

[Mechan1k]

Originally Posted by NeishaXR8_347

What that thing does that is missing is block off the pipe that goes to the water pump, in not having this it will take it a bit longer to heat up.

These are the ones that are needed for the dedicated LPG models as coolant still needs to run through the pipes to the converter when cold.

[NeishaXR8_347]

Originally Posted by Mechan1k

These are the ones that are needed for the dedicated LPG models as coolant still needs to run through the pipes to the converter when cold.

This is correct as they hack these pipes up when fitting the convertor.

I dont know why they didnt sell you the correct one as the type you had originally is the one it needs, the whole idea is to bring the engine up to operating temp quicker. But it may still work fine as JC has already told you he has one without and has no issues with it.

[mattp]

Right, thanks NeishaXR8, I'll go back tomorrow and tell him to give me the right one. I've had it in my car already but haven't run it. He can wear it.

[JC]

I wouldn't worry about it - it's a thermostat, it still does the job, and heating time may vary by 30 seconds or so - no biggie really.

[FRDTUF]

I think you'll find that ford has supper seeded them to be the short type... after market you can still buy both...

[mattp]

OK, if the heating time is only varied by that little that's fine.... I had visions of it varying by minutes. If it's not going to hurt anything I'll leave it, I might just ring Ford tomorrow and confirm it's superceded and that this is what they're using now. Cheers, Matt.

[aussiblue]

Actually, as I found out the hard way, if you run a relatively high glycol (say 50% antifreeze) mix having a dual acting or skirted thermostat (the one with the poppet valve on the bottom that closes off the bypass system when the thermostat opens) can be very critical. In cold conditions or high elevations the coolant in the radiator can become viscous with the cold air blowing through it so there is less resistance for the coolant to continue flowing through the hot less viscous bypass system and you will get a momentary heat soak and eventually a blown head gasket. Get the originally specified dual acting one and be safe...... particularly in the hills/mountains or like me drive past a lake or a misty valley in the early morning or evening around the time when the thermostat is due to open.

Also see http://www.vtr.org/maintain/stag-cooling.shtml
http://www.expeditionlandrover.info/Thermostats.htm
From the last link:

If you use the common skirtless thermostat the by-pass opening remains open continuously regardless of engine temperature. The pump of course will pump the same amount but the flow will take the line of least resistance which is through the by-pass rather than the long way around through the radiator.

This will cause your engine to run hotter in warm weather. The temperature gauge sender is located at the front of the engine by the thermostat. With most of the water bypassing the radiator, temperatures at the rear of the head can be significantly higher than your temperature gauge indicates. The high temperature gradient can cause the head to crack.

and from the 1st link:

If you use one without the blanking disk, the water pump will take suction from both the hot and cold sides of the radiator. In addition to raising the temperature of the coolant pumped back into the engine, this will reduce the volume of coolant flowing through the radiator.

Don't fall for the superseded part story. If need be buy a Tridon, Stant or Dayvo aftermarket one. Try to get one with the jiggle pin bleed hole rather than the more common notch or half moon cutout bleed hole that easily block.

[aussiblue]

NOT a dual acting or skirted T Stat but the white plastic ball and U shaped thing to the right is a jiggle pin.

[aussiblue]

I often wonder how many blown head gaskets in E series Ford 6's are caused by fitting a single acting thermostat without people ever realising as:

a) it's an obscure issue that many mechanics and even some automotive engineers are not aware of;
b) the heat soak (rapid short term overheating - typically the temp gauge goes into the red for 15 to 30 seconds and then returns to normal) fault often occurs some time after the T stat is changed when weather conditions change (to cold mornings or evenings) or someone takes an early morning or evening mountain/hill or lakeside drive; and
c) If you don't run a high glycol mix the heat soak wont happen or be so obvious to indicate you have a problem but you will still have the heat gradient differential problem and slight overheating from drawing coolant from the bypass system that will likely lead to a blown head gasket.

[aussiblue]

Also called a reverse poppet or bypass style thermostst

http://www.are.com.au/feat/techt/thermostat.htm

A vehicle fitted with a bypass style thermostat must always have he correct bypass thermostat fitted. Vehicles fitted with non-bypass hermostats must always be fitted with the correct non-bypass thermostat. The fitting of an incorrect thermostat will cause the engine to run differently to how it was designed. Overheating and subsequent engine damage can be caused by using an incorrect thermostat

and

Non-Bypass Thermostat In A Bypass Application -
In this situation there is no secondary valve that will block off the
bypass port when the engine warms up (Figure 4). This will cause
hot coolant to continue to circulate through the engine without
going to the radiator. The engine will run hotter than required and
may cause a failure of other components in the cooling system.

[mattp]

Thanks a lot aussiblue, you really seem to know your stuff on this!!

[aussiblue]

Yes I had the superseded stock story tried on me many years ago and as result took a certain company to the small claims tribunal over the resultant damage.

It initially took me some testing and experimentation with logging multimeter thermometers attached to hoses etc to work out what was happening with the coolant flow when using the wrong T stat and why it caused a head gasket to blow and would cause a short rapid heat soak when the car was driven past the local lakes on cold misty mornings. It was only later I found some texts and net references explaining why it happened.

[mattp]

I'm gonna hit Ford up tomorrow for the correct part, if they don't have it I'll be after my money back.... Dunno how they'll take that.

[aussiblue]

I almost certain they'll swap it but if not just ask them to warrant in writing that it won't cause a problem and blow your head gasket.

Take a copy of this thread along and get them to check with the Ford engineers that worked on the EA/EB/ED series and the problems they had when they tried this parts rationalisation approach before in the mid 90's in terms of cars used in mountainous areas and in cold valleys etc. They shouldn't have forgotten about this issue yet. And if they designed the car for a bypass T-stat why are they suggesting it should suddenly be OK not to use one.

[Mechan1k]

Originally Posted by aussiblue

Also called a reverse poppet or bypass style thermostst

http://www.are.com.au/feat/techt/thermostat.htm



and

Interesting indeed ... I might check my thermostat again .. and see if i have the correct one in there ... just in case. Have had it replaced twince now ... and the vehicle still overheats under load .... although temp tests show that it isn't ... might be a long shot ... no harm in trying it though..

[mattp]

Well I went back yesterday and swapped it no dramas, even got $5.35 back since it was cheaper. But, the guy said what they gave me originally was what Ford Motor Company recommends now (the skirtless one), and that's what they use in all their services (!) (So probably worth checking Mechan1k!), but when I asked him why would they use a non-bypass thermostat in a car designed to use a bypass one, he said, they don't need to explain it, that's just what they recommend. Useless. Get this though, he then says not to come back complaining if I bugger my engine by using the skirted bypass one. Morons. I'm going to ruin my engine by putting in an OEM part that the car was designed to use and left the factory with. !? Anyway, new one is in, all is good again. Thanks for everyone's input, especially aussiblue. Cheers, Matt.

[NeishaXR8_347]

Originally Posted by mattp

Well I went back yesterday and swapped it no dramas, even got $5.35 back since it was cheaper. But, the guy said what they gave me originally was what Ford Motor Company recommends now (the skirtless one), and that's what they use in all their services (!) (So probably worth checking Mechan1k!), but when I asked him why would they use a non-bypass thermostat in a car designed to use a bypass one, he said, they don't need to explain it, that's just what they recommend. Useless. Get this though, he then says not to come back complaining if I bugger my engine by using the skirted bypass one. Morons. I'm going to ruin my engine by putting in an OEM part that the car was designed to use and left the factory with. !? Anyway, new one is in, all is good again. Thanks for everyone's input, especially aussiblue. Cheers, Matt.

Mate what can i say, when he told you he doesnt need to explain it he may aswell said "im just a pen pusher and really dont know what a thermostat does". The one that was designed for it is correct.

[JC]

Originally Posted by NeishaXR8_347

Mate what can i say, when he told you he doesnt need to explain it he may aswell said "im just a pen pusher and really dont know what a thermostat does". The one that was designed for it is correct.

The problem is, they're both designed for it, so how do you know which one is the best for a particular application? Found this on drive.com, which seems to contradict aussieblue's advice, which may have suited E series cars, but it would seem that the original Ford thermostat (the longer one) actually caused problems on the AUs:

What to look for
Ford Falcon AU (1998-2000)
Engine and transmission
Premature radiator failure encouraged Ford to upgrade this particular item; the thermostat was also modified. There were some air-conditioning problems. Oil leaks from the front bolt in the timing case tended to occur fairly early and were repaired under warranty.

Link = http://www.drive.com.au/Editorial/Ar...leID=8611&vf=1

[mattp]

Hmmmm, I wonder what the definitive answer is then. I'm happy since the new one is the same as the old one but it would be interesting if they DID have an explanation as to why they're now using the skirtless thermostats. I can't see how it would cause major problems though. The AU's are much less likely to blow head gaskets than the E's anyway, with the upgraded metal ones they brought in on the AU's.

[aussiblue]

Yes; I understand for some reason they found that AU's and later sixes work better with the skirtless single acting ones and that was why they tried to standardise on one type. Ford are not very forthcoming on this question as I expect they are concerned able assuming any liability. I guess the definitive answer is that all the cooling systems in Ford inline 6's from 1988 onwwards were less than perfect, prone to causing head gasket failures and fussy about what T stat were used with them

[JC]

Originally Posted by mattp

Hmmmm, I wonder what the definitive answer is then.

I'm wondering the same thing. For me, if something is superseded, then it's better to use the new item, because it's normally done for a reason. I know one early fix for series 1 AU thermostats was to drill a 3mm hole in the top to keep coolant flowing through at all times, so I figure the newer skirtless one is the answer to all the thermostat issues learned by Ford from E series through early AUs.

[aussiblue]

No the EA's to ED need definately need the dual acting one. BTW I usually just go to new posts so I hadn't realised this was the AU forum when I first posted; sorry. I think what happened was they found there was a problem using the dual acting one on the AU and tried to standardise on the skirtless one without initially realising it would then cause problems in the EA-ED series. All the EL & EF I have seen also have dual acting ones fitted but I am not sure if is a big issue with them or not. Nonetheless I am running one in my son's EF.

[mattp]

So I should have stuck with the skirtless one?!

[JC]

Originally Posted by mattp

So I should have stuck with the skirtless one?!

For an AU1, I don't think it will matter.

[mattp]

Cool, it's had a skirted one in it for the last 150 thousand kays, a few more can't hurt