Thermostat

GordnadoCRD · **Posted:** Mon Oct 24, 2016 6:43 pm

jws84_02 wrote:

Holy sh*t......does any thread Jeff is involved not get out of hand?

In my brief observation it seems that any thread that mentions his product gets quite promptly fire-bombed. Not with flames against his product, but against him personally and against his chosen business model. These flames prompt him to defend himself, and get sidetracked from promoting his product.

If he intends to grow his business, my suggestion to him is to recruit someone competent to handle the marketing. Freeing time for him to pursue the engineering and manufacturing issues and new product development. It also would help insulate him from having to defend himself, his product, and his business.

Turning over control of a part of one's business to someone you just hired for that is a risky proposition, but if you hire someone competent and keep them motivated it's worth it. Perhaps someone that has already purchased and uses his product would be interested in such a business opportunity.

Just a suggestion, but something definitely needs to be changed so he's not wasting time defending against flamers.

Locked KJ · **Posted:** Mon Oct 24, 2016 6:57 pm

While I have no interest in getting involved in some of the nonsense going on here. Everybody is entitled to an opinion. Although I have less value for a opinion of a product someone has not actually used.

I recently rebuilt the top end of my crd. After reading a pretty informative thread that has since disappeared :evil:

, I decided to purchase a model 001. I think it is the best solution thus far for the this little engine and it's overheating and not heating enough problems.

I was thoroughly impressed with the fit and finish. It also came with a much nicer gasket than the one that came with the head gasket kit from idparts. I'm trying to build this little crd to last a long time. I think over the course of the next 15+ years of ownership (hopefully) it will be equal in cost to the three oem thermostats I would've bought. If you figure in my time saved in labor I'll have come out ahead.

Now as far as how the product performs. I'd say quite well. The engine gets up to full operating temperature in about 3 to 4 minutes on my morning commute. Which probably equates to about 2.5 miles. We'll see if that changes as it gets colder. The coldest I've seen so far is about 45°F. Once the needle is up it does not waver one bit.

I will say this. I bought this liberty and immediately had a number of problems with it. I didn't really even drive it but twice when I found it was burning coolant. I don't have any experience with how this vehicle ran or drove new or even slightly used. So I can't say something like "it heats up way faster and has hotter floor heat than the factory thermostat". That would be dishonest because in didn't drive it enough to even notice what the factory part did. I also have no idea whether or not it has increased the mileage.

I do however believe in the theory that the model 001 is based on. I also believe I will have many years of trouble free service from this item.

Thank you Jeffrey for making an awesome product
.

4wheeldeal · **Joined:** Thu Mar 15, 2012 11:11 pm **Posts:** 70

So mines at 1/4 on the gauge and wont get warmer. Can i get a warmer t stat for my cold canadian winters that will still be ok come summer? Or stock? Thanks

jws84_02 · **Posted:** Mon Oct 24, 2016 9:39 pm

4wheeldeal wrote:

So mines at 1/4 on the gauge and wont get warmer. Can i get a warmer t stat for my cold canadian winters that will still be ok come summer? Or stock? Thanks

Yours has failed stuck open. Either replace with another oem thermostat or another option

geordi · **Posted:** Tue Oct 25, 2016 12:22 am

4wheeldeal wrote:

So mines at 1/4 on the gauge and wont get warmer. Can i get a warmer t stat for my cold canadian winters that will still be ok come summer? Or stock? Thanks

This is how you know that the thermostat has failed. It is stuck open. As of right now, you have effectively no thermostat, so even the stock replacement will be better than what you don't have right now.

Sent from my iPad using Tapatalk HD

Ceearedeedriver · **Joined:** Fri May 06, 2016 8:44 pm **Posts:** 177

4wheeldeal wrote:

So mines at 1/4 on the gauge and wont get warmer. Can i get a warmer t stat for my cold canadian winters that will still be ok come summer? Or stock? Thanks

As the previous two posts have pointed out your thermostat has failed. Unless you have the equipment and skills to do a DIY OE housing mod the choices you're left with are the HDS Model 001 or a replacement OE housing. There's plenty of information on the pros and cons of both of these solutions on this forum. Either will get you back up to an appropriate operating temperature. The choice is yours.

In your search you may also come across a lower cost Crown branded copy of the OE housing. Don't be tempted by this one, it's not recommended around here due to the high number of failures.

WWDiesel · **Posted:** Tue Oct 25, 2016 10:54 am

Parts with the "Crown" brand name on them have a history around here of early failure. "Crown" is a cheaply made chinese copy knock off brand and synonymous with poor quality parts.... :shock:

Right now, Factory Mopar Parts has the best price for the OEM Mopar Thermostat:>MOPAR 5142601AA THERMOSTAT $106.72

http://www.factorymoparparts.com/oe-mopar/5142601aa

justinmc · **Posted:** Wed Oct 26, 2016 1:31 pm

So, what is the issue with using an inline thermostat? That seems to be the cheapest simplest solution to a failed open OEM thermostat. Some people mention irregular heating of the head/block, but aren't all the bypass ports before the thermostat still circulating coolant so how would this be a problem?

The only downside seems to be the inline thermostat is further away from the original failed thermostat so it may not open quick enough to dissipate the heat properly?

Justin.

flash7210 · **Posted:** Wed Oct 26, 2016 1:54 pm

justinmc wrote:

So, what is the issue with using an inline thermostat? That seems to be the cheapest simplest solution to a failed open OEM thermostat. Some people mention irregular heating of the head/block, but aren't all the bypass ports before the thermostat still circulating coolant so how would this be a problem?

The only downside seems to be the inline thermostat is further away from the original failed thermostat so it may not open quick enough to dissipate the heat properly?

Justin.

The way the factory thermostat is setup, when cold the main outlet is closed and the bypass outlet is open. When it warms up the main outlet opens and the bypass outlet closes.
If the factory thermostat fails in the open position and a inline thermostat is placed into the upper rad hose, the bypass is closed and there will be insufficient coolant flow until the inline thermostat opens.

It has never been conclusively proven that the inline thermostat has caused blown head gaskets or cracked heads. However, there have been too many reports of folks having a cracked head while using the inline thermostat to just consider it a coincidence. Myself included.

justinmc · **Posted:** Wed Oct 26, 2016 2:16 pm

flash7210 wrote:

The way the factory thermostat is setup, when cold the main outlet is closed the bypass outlet is open. When it warms up the main outlet opens and the bypass outlet closes.
If the factory thermostat fails in the open position and a inline thermostat is placed into the upper rad hose, the bypass is closed and there will be insufficient coolant flow until the inline thermostat opens.

It has never been conclusively proven that the inline thermostat has caused blown head gaskets or cracked heads. However, there have been too many reports of folks having a cracked head while using the inline thermostat to just consider it a coincidence. Myself included.

So, what mechanism is closing the bypass? If it's based on back pressure from the OEM thermostat surely there is still enough back pressure from an inline thermostat. Isn't the upper radiator hose the only outlet after the OEM thermostat?

Someone should point a thermal camera at the engine and see if it picks up this assumed problem because otherwise it's speculation. Having an inline thermostat installed while a problem occurs may or may not be related depending on other factors that could have changed at the same time.

Also, these mods are done later in the engine life so what's the rate of failure with and without inline thermostats, etc?

Justin.

flash7210 · **Posted:** Wed Oct 26, 2016 2:36 pm

Quote:

So, what mechanism is closing the bypass? If it's based on back pressure from the OEM thermostat surely there is still enough back pressure from an inline thermostat. ?

The action of the opening thermostat closes the bypass. It all moves together.

Quote:

Someone should point a thermal camera at the engine and see if it picks up this assumed problem because otherwise it's speculation. Having an inline thermostat installed while a problem occurs may or may not be related depending on other factors that could have changed at the same time.

Sounds like a great idea. Are you volunteering to do that?
Not sure how well it would work considering you would only see temp on the outside surface of the head. You wouldn't see whats happening in the passages inside the head.
My head had cracks around the exhaust valve seats of cylinders 2, 3, and 4.

I had a theory that the rearmost cylinders were running hotter than the front. So I attached a temp sensor to the side of the head between cyl 3 and 4.
So far, it has proven my theory wrong.
But this was added after I had replaced my head and modified my thermostat.

picture added for clarity

geordi · **Posted:** Wed Oct 26, 2016 2:53 pm

You bring up good points, and ask for the same data that I have asked for on several occasions, and received attacks as a response from a former vendor. Apparently my asking for proof of claims of direct links to failure modes is so out-of-line, that it also warrants complaints / secret whining to the one who runs this entire forum.

The factory thermostat does have a bypass function, but nobody has ever shown any evidence (not even an IR gun pointed at various places) that shows the temperature with an inline installed. I do not believe the system is completely closed off, but that is only a belief - I also do not have any data to share, but I am not selling a product and simultaneously making claims to engineering results or unsuitability of another option without ever producing data to back up the claims.

Yes, the inline is a cheap option. Yes, it does not replicate the factory bypass function. These facts are not in question. What is not proven however is any link between the inline (or lack of any thermostat) and cracked heads. I have worked on *many* of these now, some with the inline, most without. I have yet to speak with anyone or see a vehicle that did have a cracked head. I do not believe this is a problem related to the thermostat.

As a design, diesel engines will tend to run very cold when in light operation, this is primarily due to having very little excess waste heat to share with the block. They are very efficient, which means the heat from the fuel is transferred mostly into work. That is why you may desire a hotter thermostat to reduce the very effective cooling performance of the water system and try to retain some of that heat within the block to aid in even better combustion. Certainly the factory thermostat is not good at this job. But I have also not seen any "hotspots" develop (and I personally HAVE taken temp readings with an IR gun and posted the pictures here) and the difference around the engine was a mere 2 degrees from place to place. This is close enough to be within statistical noise. For a "hotspot" to cause a head crack failure, I would expect many tens of degrees difference, if not even more.

So like many others, I ask again: Where is the data?

geordi · **Posted:** Wed Oct 26, 2016 2:56 pm

flash7210 wrote:

Quote:

So, what mechanism is closing the bypass? If it's based on back pressure from the OEM thermostat surely there is still enough back pressure from an inline thermostat. ?

The action of the opening thermostat closes the bypass. It all moves together.

Quote:

Someone should point a thermal camera at the engine and see if it picks up this assumed problem because otherwise it's speculation. Having an inline thermostat installed while a problem occurs may or may not be related depending on other factors that could have changed at the same time.

Sounds like a great idea. Are you volunteering to do that?
Not sure how well it would work considering you would only see temp on the outside surface of the head. You wouldn't see whats happening in the passages inside the head.
My head had cracks around the exhaust valve seats of cylinders 2, 3, and 4.

I had a theory that the rearmost cylinders were running hotter than the front. So I attached a temp sensor to the side of the head between cyl 3 and 4.
So far, it has proven my theory wrong.
But this was added after I had replaced my head and modified my thermostat.

picture added for clarity

Hey Flash - I don't believe there are water jackets directly adjacent to the valve seat area, but let me ask you this: At the time of the head cracking, what was your engine EGR setup? Was it functional? Were you running a tune or any other mods? My theory about the valve failures is all around the exhaust valves, and circles around the idea of excessive cylinder temps when there shouldn't be.

WWDiesel · **Posted:** Wed Oct 26, 2016 3:05 pm

To understand, you have to look inside the VM diesel thermostat! It is a two dimensional type thermostat in that it has two valves in one housing. As the top part of the thermo valve opens as coolant temperature from the head outlet rises it allows flow to the radiator and simultaneously at the same time closes off the bottom part of the thermo valve to stop the flow to the bypass outlet. The movements are nonlinear meaning that whatever movement the top part moves in an open direction the bottom part closes off at the same movement and rate....

The problem with an in-line thermostat is: If the OEM thermostat is stuck in a 100% open position, the bypass is fully closed and allows NO flow through the head until the in-line thermostat starts opening up to allow flow to the radiator. With the bypass circuit closed off, the water pump is pumping against a deadhead and no flow is allowed through the head to ensure even heating as the engine heats up...
The theory is during this period it is possible that the coolant temperature may get extremely high before it migrates enough to the in-line thermostat enough to heat its thermo bulb to make it start opening. :shock:

If you are determined to install an in-line thermostat, which I would NOT recommend, you should install it as close as possible to the OEM thermostat outlet and drill a 1/4" (0.25) opening in the thermostats plate to help facilitate quicker warmup and response time by the in-line thermostat.

flash7210 · **Posted:** Wed Oct 26, 2016 3:22 pm

Quote:

Hey Flash - I don't believe there are water jackets directly adjacent to the valve seat area, but let me ask you this: At the time of the head cracking, what was your engine EGR setup? Was it functional? Were you running a tune or any other mods? My theory about the valve failures is all around the exhaust valves, and circles around the idea of excessive cylinder temps when there shouldn't be.

EGR had been disabled in one form or another for at least 60k miles prior to the cracking.
While I had the head off, I removed the EGR valve and confirmed that the EGR cooler was leaking. But this was a non-factor due to the EGR outlet-to-intake being blocked with the Sasquatch stage 1 kit.
Evidence of the cracks was present before the addition of a tune or any turbo mods.

There absolutely HAS to be a cooling jacket in the vicinity of the exhuast valves.
Here is why:
1. The exhaust valves get extremely hot. They transfer heat to the valve seat every time they close. That heat must also transfer to a water jacket.
2. The cracks around the exhaust valve seats were leaking coolant into the cylinder and exhaust ports. Therefore, there must be a water jacket nearby for coolant to leak from.

I still have my old head. Maybe I could have it cut apart to see exactly where the water jackets are.

justinmc · **Posted:** Wed Oct 26, 2016 3:50 pm

flash7210 wrote:

Sounds like a great idea. Are you volunteering to do that?
Not sure how well it would work considering you would only see temp on the outside surface of the head. You wouldn't see whats happening in the passages inside the head.
My head had cracks around the exhaust valve seats of cylinders 2, 3, and 4.

I had a theory that the rearmost cylinders were running hotter than the front. So I attached a temp sensor to the side of the head between cyl 3 and 4.
So far, it has proven my theory wrong.
But this was added after I had replaced my head and modified my thermostat.

I only have a cheap thermal camera with a 206x156 resolution but I could try it. Like you say unless the temp differences are extreme it may only be noticeable inside. Thanks for the pic that helps a lot.

Aluminum is a great heatsink metal so I doubt it would have much trouble warming up quickly and evenly with any sort of flow, but the cast iron could take awhile.

justinmc · **Posted:** Wed Oct 26, 2016 4:03 pm

WWDiesel wrote:

To understand, you have to look inside the VM diesel thermostat! It is a two dimensional type thermostat in that it has two valves in one housing. As the top part of the thermo valve opens as coolant temperature from the head outlet rises it allows flow to the radiator and simultaneously at the same time closes off the bottom part of the thermo valve to stop the flow to the bypass outlet. The movements are nonlinear meaning that whatever movement the top part moves in an open direction the bottom part closes off at the same movement and rate....

The problem with an in-line thermostat is: If the OEM thermostat is stuck in a 100% open position, the bypass is fully closed and allows NO flow through the head until the in-line thermostat starts opening up to allow flow to the radiator. With the bypass circuit closed off, the water pump is pumping against a deadhead and no flow is allowed through the head to ensure even heating as the engine heats up...
The theory is during this period it is possible that the coolant temperature may get extremely high before it migrates enough to the in-line thermostat enough to heat its thermo bulb to make it start opening. :shock:

If you are determined to install an in-line thermostat, which I would NOT recomend, you should install it as close as possible to the OEM thermostat outlet and drill a 1/4" (0.25) opening in the thermostats plate to help facilitate quicker warmup and response time by the in-line thermostat.

That's what I've been trying to find out. It's hard to get an inside view. I'm not sure if my failed OEM is fully open but I get temps around 135F according to the OBDII reading. I just bought a used OEM thermostat for $30 so I'll probably install that but was just curious about how an inline one would work. It sounds like an inline thermostat with a hole drilled in it would be better than running cold with a failed OEM thermostat but with possible risks of uneven heating etc.

papaindigo · **Posted:** Wed Oct 26, 2016 4:14 pm

Up front I am not recommending the inline option but when the inline option was first discussed I strongly recommended a hole in the inline tstat skirt on the "up" side. This is an old time mechanic trick from back in the days of little or no bypass. The purpose was to prevent overheating by guaranteeing the some coolant got past the tstat if if failed closed. By adding this hole you a) provide relief if the bypass is partially or fully closed and b) by being on the "up" side the hole allows air to bleed back to the coolant tank to keep the system air tight.

Above said use the OEM tstat; mods to the OEM tstat that allow use of a normal $10 tstat inside that housing; or TDFs housing. I've used Kaps mode to the OEM and now have TDFs; both work fine.

WWDiesel · **Posted:** Wed Oct 26, 2016 8:53 pm

justinmc wrote:

That's what I've been trying to find out. It's hard to get an inside view. I'm not sure if my failed OEM is fully open but I get temps around 135F according to the OBDII reading. I just bought a used OEM thermostat for $30 so I'll probably install that but was just curious about how an inline one would work.

Quote:

It sounds like an inline thermostat with a hole drilled in it would be better than running cold with a failed OEM thermostat but with possible risks of uneven heating etc.

True to a point, but not entirely! Running too cold is not good for your engine either, diesels operates best in a certain temperature range... :roll:

Everyone is giving you the same advice; do not use an in-line thermostat, it simply is not worth the risks and possible consequences of a possible head gasket failure or worse yet a cracked head not to mention the high costs involved. Either one can get very expensive very quickly when having to deal with them!!!
The absolute best and safest solution is to replace thermostat with a new OEM thermostat from one of the on-line vendors like Factory Mopar Parts that has the best price for the OEM Mopar Thermostat.>>http://www.factorymoparparts.com/oe-mopar/5142601aa
or if you got plenty of funds order one of the high dollar custom thermostats from a former vendor on this forum, they are nice, but very pricey.... :shock:

justinmc · **Posted:** Wed Oct 26, 2016 9:06 pm

WWDiesel wrote:

Quote:

It sounds like an inline thermostat with a hole drilled in it would be better than running cold with a failed OEM thermostat but with possible risks of uneven heating etc.

True to a point, but not entirely! Running too cold is not good for your engine either, diesels operates best in a certain temperature range... :roll:

Everyone is giving you the same advice; do not use an in-line thermostat, it simply is not worth the risks and possible consequences of a possible head gasket failure or worse yet a cracked head not to mention the high costs involved. Either one can get very expensive very quickly when having to deal with them!!!
The absolute best and safest solution is to replace thermostat with a new OEM thermostat from one of the on-line vendors like Factory Mopar Parts that has the best price for the OEM Mopar Thermostat.>>http://www.factorymoparparts.com/oe-mopar/5142601aa
or if you got plenty of funds order one of the high dollar custom thermostats from a former vendor on this forum, they are nice, but very pricey.... :shock:

Not everyone is saying that but it seems to be a popular opinion. The proof of damage due to the inline thermostat option is vague and circumstantial. I haven't seen any hard facts, just opinions and speculation so far. As I mentioned I've already purchased a used working factory thermostat for $30. It is being shipped to me so I should have it soon.

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