Temp gauge

Bama KJ · **Joined:** Sat Oct 01, 2011 7:28 am **Posts:** 12

Where should the temp gauge normaly run. 1/2 ,1/4,?

papaindigo · **Posted:** Sun Oct 02, 2011 8:11 am

Take a look at http://www.greendieselengineering.com/f ... st/19.page

You should reach normal operating temp from a cold start in 5-10 miles depending on the ambient temp possibly a bit longer in really cold northern areas. The gauge needle should ride between dead vertical and 1 tick left of dead vertical. Our tstats tend to fail either open or by opening too early, according to kap because the spring gets weaker over time. If ambient is 70F+ and/or you are running AC that doesn't matter too much as the heat load will bring the temp gauge up to normal but it might take a bit longer. Below 70F especially with the cabin heat on the system cannot get up to normal operating temp and the temp gauge will top out at 2 ticks left of vertical or lower as time goes by, eventually reading between 1/4 and 3/8.

Solution; new OEM tstat, kaps mod when he gets caught up, or leave the failed/failing OEM tstat in place and install an in-line tstat in the main coolant line from the tstat to the radiator see http://www.amazon.com/Meziere-WN0072-In ... 131&sr=1-2 with a 195 degree Chevy thermostat. The latter appears to work fine, search the forum, IF you drill a 3/32" hole in the tstat skirt before the install. The purpose of the hole is to allow coolant flow thru the in-line tstat as the engine warms up but before the tstat opens. Without the hole the in-line tstat essentially blocks flow to the radiator until convection of heat thru the water is enough to open the in-line tstat which results in a temperature spike because the in-line tstat opens late.

Bama KJ · **Joined:** Sat Oct 01, 2011 7:28 am **Posts:** 12

Thanks for the info. It is reading at 1/4 now with the wearher at 70o. Back in the summer it will read 1/2 mark. With this lower temp this will cause power loss correct.

papaindigo · **Posted:** Sun Oct 02, 2011 12:05 pm

Some power loss, not terribly noticable, and about a 10% drop in mpg. Best go ahead and replace the tstat before winter sets in. Cost is a touch over $100 plus $2 for the gasket and be sure to use HOAT antifreeze (Mopar or Xerex G-05). Unless of course you decide to go in-line.

Removal of the existing tstat is a bit tricky and you have to be careful not to mix up bolts during the reinstall.

Drop me an email if you want a copy of my notes on the topic.

Kgeisler2010 · **Joined:** Sun Sep 04, 2011 9:56 pm **Posts:** 66

Well reading this i think mt tstat may also be out. Has anyone on here did the in line tstat if so how did it work out

papaindigo · **Posted:** Sun Oct 02, 2011 2:08 pm

arengant did what is, as far as I can tell from the chat, a successful install. See viewtopic.php?f=5&t=61180&hilit=thermostat

Send a PM or email to see if the inline is still running ok. We chatted a bit during the install/testing process and my earlier post outlines the outcome. Short version is in-line without a hole in the skirt causes temp spike before it opens vs. in-line with a 3/32" hole in the skirt seems to work just fine.

Bama KJ · **Joined:** Sat Oct 01, 2011 7:28 am **Posts:** 12

Just ordered a inline Meziere Enterprises WN0072 thermostat. $76 bucks E Bay.
Now would a 205deg be the best to use.

papaindigo · **Posted:** Tue Oct 04, 2011 8:41 am

Amazon $54.99 w. free shipping for future reference. I would be inclined to stick with a 195 deg F tstat. Based on chat on LOST and the GDE forum 195 appears to be what recent diesels, including VM, are using in Europe. Going much higher may cause issues with engine cooling especially if you are using the temperature triggered viscous fan.

irollgen4s · **Posted:** Tue Oct 04, 2011 2:35 pm

my mileage went from 20 town to 12 town when my Tstat went bad. Most of the time because it wouldnt shift into overdrive due to the temperature not being high enough, plus most of my driving is short in town.

black dog · **Joined:** Sat Dec 27, 2008 11:31 pm **Posts:** 46

I've got 10k on my in line with 195 thermostat and it works like a charm!

Bama KJ · **Joined:** Sat Oct 01, 2011 7:28 am **Posts:** 12

Just installed the inline with a 195 deg plus a 3/32 weep hole. Man does it run better and see ms to have more power. Checked on a new thermostat housing and WHAT $145 bucks. No way. I will wait till i get my shop built back.

dkenny · **Posted:** Thu Oct 06, 2011 8:06 pm

my wife jeep has the same bad/weak thermostat..
today I ordered an inline from amazon..$55..free shipping

-dkenny

naturist · **Posted:** Mon Oct 10, 2011 10:13 am

The first time I ever saw a thermostat of the sort on the Libby, it was on a BMW 2002 back in 1969. They were expensive then, too, as I recall, about $14 compared to the going $3 for the usual sort.

The thing that distinguishes these from the usual, is that the usual (and I assume the "inline" folks are talking about here) is that they work by mixing hot water exiting from the head with cold coming from the radiator to get a constant intake temperature for the water pump to circulate in the block/head.

The standard sort, and the "inline" one I assume, are much simpler, and work by merely blocking the exit of hot water until it reaches operating temp.

Back in 1969, BMW said that they changed to the mixing type because they'd had some problems with folks cracking the block while running hard through the Alps because the intake water was too cold and stressed the hot block.

So I kinda wonder: are folks putting their engine at undue risk in THIS application by using the cheaper inline t-stat instead of the more expensive OEM "mixing" type t-stat? I recon we won't know until really cold weather sets in, and enough people test the results. I don't intend to rain on the parade here, I just wanted to 'splain why I think I'll stick to the expensive t-stat and alert folks to the fact there is a little bit of risk here that is not obvious to the naked eye, and let's all hope the Law of Unintended Consequences does not apply here.

papaindigo · **Posted:** Mon Oct 10, 2011 11:08 am

Unless I'm completely mistaken the CRD stock tstat doesn't "mix" anything. The tstat has essentially 4 outflows and 1 inflow. The inflow is the rectangular hole in the head where the tstat bolts on and ALL water passing thru the tstat comes from there. According to MrMopar the very bottom port (aluminum fitting) is the by-pass port connected to the water-pump inlet, the large plastic port connects to the viscous heater, going then to the heater core, and the small port is the de-gas flow (constant air bleed) to the plastic tank on the firewall. The 4th outflow is the big one going to the radiator. During warm up the 4th outflow is closed and flow is directed to the bypass, viscous heater, and to a limited extent the air bleed. As the engine warms up the bypass closes and flow is redirected to the 4th outflow and on thru the radiator and from the radiator into the engine block. In other words what's cooled by the radiator is directly returned to the engine no mixing involved. What regulates the coolant temp is a combination of the tstat, forcing a minimum coolant temp, and the radiator in combination with the viscous fan keeping the coolant temp from going too high.

The typical failure mode of our tstats, per kapalczynski, is for the spring to get weak (commonly after 40-50k miles) causing the tstat to "open" too soon. Since our tstats are, to my mind, upside down this translates to the open tstat blocking the bypass before proper operating temperature is reached and diverting that flow to the radiator which then cools that already too cool fluid so that proper operating temperature is never reached. The in line tstat serves the purpose of blocking that early/too cool flow to the radiator until the in line tstat opens. The potential problem with the in line, experienced by some early on, is that a complete blockage of the flow to the radiator by a closed in line tstat combined with the OEM early closure of the bypass can cause a spike in the engine temp before the in line tstat opens and things settle back down to the normal operating temp as controled by the in line tstat. The solution is a trick I was taught years ago to prevent or minimize overheating on tstats that typically failed closed thereby shutting off all flow to the radiator. That trick is to drill a small hole in the tstat skirt so that there is always some flow past the tstat. On those older engines this provide for some flow if the tstat failed closed (e.g. you would see the temp go up but not redline and know the tstat needed replacing). In our situation the hole in the skirt removes the blockage I mentioned and causes the inline tstat to warm up as the coolant warms up and to open when the proper temp is reached.

As to over cooling in 1969, that may have been a real problem back then but should not be a big issue in today's engines with a properly designed system although I do know folks in extremely cold areas that run partial radiator air flow blocks to keep engine temp up.

arengant · **Posted:** Thu Oct 13, 2011 7:34 am

still liking my inline 195 degree stat

with 1/8th in hole drilled

dirtmover · **Posted:** Thu Oct 13, 2011 8:13 am

papaindigo wrote:

Cost is a touch over $100 plus $2 for the gasket and be sure to use HOAT antifreeze (Mopar or Xerex G-05).

Been procrastinating on this but really need to do it before winter. I seem to recall someone suggesting that it could be changed without losing any coolant but can't find the post. Can someone confirm this one way or the other. I'd like to know where and how to extract the coolant so than I can reuse it.

papaindigo · **Posted:** Thu Oct 13, 2011 9:48 am

No matter what you do (OEM replacement or in line install) you are going to be opening the system which will cause the coolant to drain from the plastic tank on the firewall and out of the engine down to the lowest level of the opening created. If you want to reuse that coolant, as opposed to "losing" and replacing it, on a cold engine you will need to open the drain cock at the bottom passenger side of the radiator (see viewtopic.php?f=98&t=56398 for the tool to use), undo the cap on the plastic tank and it helps to open the bleed cap on the top passenger side of the radiator and drain all of the coolant out of the plastic tank plus about that much more into a bucket. That should lower the coolant level enough to do the swap without losing more coolant. After the swap is done pour the coolant from the bucket, strain if need be, back into the plastic tank (I'd leave the bleed valve open until fluid begins to come out of it). When done the fluid level in the plastic tank should be at or ideally a bit above the mid point, add if needed. Drive around until you get to operating temp to purge any air in the system, let engine cool, check fluid level in tank, should go down a bit, add if needed.

Temp gauge

Who is online