2000 D2 running too warm
#11
12-13-2011, 03:13 PM
#12
12-13-2011, 07:09 PM
Super Moderator
Sensor is shown on bottom of rad, passenger side, back of rad. Connector is C0424, but is one of the few that has no picture.
As to speed up makes it instantly change temp, does sound like pressure, but... could also be increased flow puts more hot water thru those little metering holes and activates the stat.
Looking at this from the RAVE could certainly explain this at idle:
IMHO owners might relax the heater quick performance design to reduce overheating.... may be that an oem stat handles this better than a knock off.
As to speed up makes it instantly change temp, does sound like pressure, but... could also be increased flow puts more hot water thru those little metering holes and activates the stat.
Looking at this from the RAVE could certainly explain this at idle:
The by-pass flow valve is held closed by a light spring. It operates to further aid heater warm-up. When the main valve
is closed and the engine speed is at idle, the coolant pump does not produce sufficient flow and pressure to open the
valve. In this condition the valve prevents coolant circulating through the by-pass circuit and forces the coolant through
the heater matrix only. This provides a higher flow of coolant through the heater matrix to improve passenger comfort
in cold conditions.is closed and the engine speed is at idle, the coolant pump does not produce sufficient flow and pressure to open the
valve. In this condition the valve prevents coolant circulating through the by-pass circuit and forces the coolant through
the heater matrix only. This provides a higher flow of coolant through the heater matrix to improve passenger comfort
IMHO owners might relax the heater quick performance design to reduce overheating.... may be that an oem stat handles this better than a knock off.
#13
12-13-2011, 08:21 PM
Super Moderator
IMHO if oem stat does not improve it, here are some things that might:
1. New high flow water pump - would develop more pressure at lower rpm, activating that valve.
2. The stat has to get warm to open, and how warm it gets decides how far open it will go. So if the four sample holes were enlarged, or additional ones drilled, stat would get warmer and open more.
1. New high flow water pump - would develop more pressure at lower rpm, activating that valve.
2. The stat has to get warm to open, and how warm it gets decides how far open it will go. So if the four sample holes were enlarged, or additional ones drilled, stat would get warmer and open more.
#14
12-13-2011, 10:16 PM
Recovery Vehicle
IMHO if oem stat does not improve it, here are some things that might:
1. New high flow water pump - would develop more pressure at lower rpm, activating that valve.
2. The stat has to get warm to open, and how warm it gets decides how far open it will go. So if the four sample holes were enlarged, or additional ones drilled, stat would get warmer and open more.
1. New high flow water pump - would develop more pressure at lower rpm, activating that valve.
2. The stat has to get warm to open, and how warm it gets decides how far open it will go. So if the four sample holes were enlarged, or additional ones drilled, stat would get warmer and open more.
IIRC, there was NO additional plug or sensor on the radiator. I believe there was the one for the transmission temp, but that is the only one I had to take off. There was something that attached to the top of the radiator, but I think it was that transmission one that just clipped on there for safe keeping. Possible problem you think? The radiator was aftermarket that was in there, as is the new one. Also, the RAVE did not mention anything about a sensor, and the only area I could see having one would be the drain screw that is near the lower hose. I also didn't see any wiring or anything, and I do not have any codes that should be there if a sensor was missing.
#15
12-14-2011, 04:29 AM
Super Moderator
Believe you are correct on tranny temp sender.
The RAVE shows the missing sensor in the engine management section of the workshop manual, on page 18-2-21, it is called a thermostat monitoring sensor. Guess it might not be on all of them.
Thought we might take the RAVE verbatim - consider when these two statements are considered at the same time:
When the main valve is closed and the engine speed is at idle, the coolant pump does not produce sufficient flow and pressure to open the valve
and
The thermostat is closed at temperatures below approximately 82
The RAVE shows the missing sensor in the engine management section of the workshop manual, on page 18-2-21, it is called a thermostat monitoring sensor. Guess it might not be on all of them.
Thought we might take the RAVE verbatim - consider when these two statements are considered at the same time:
When the main valve is closed and the engine speed is at idle, the coolant pump does not produce sufficient flow and pressure to open the valve
and
The thermostat is closed at temperatures below approximately 82
°C (179°F). When the coolant
temperature reaches approximately 82
°C the thermostat starts to open and is fully open at approximately 96°C (204°F). In this condition the full flow of coolant is directed through the radiator
So the spring loaded bypass is working as designed, turning off flow when cold condition exists, to speed warm up of passengers. And main stat opens gradually, over the range of 180 - 204 F, not on/off like a light switch. And your engine temp is in the range where the stat should be wide open (above 204 F).
So if main valve is wide open, why is bypass spring still having an effect, even at idle?
So if main valve is wide open, why is engine cooling not any better?
IMHO the combination of (bypass function still working) + (overall engine temp high) = stat thinks it is still cold..
If the hot coolant can't keep the wax pellet inside the stat at above 180F - 204F , the stat will just close off, or only open partially (like half open when it should be full open), reducing flow of coolant and heating up engine. So either increase flow of hot coolant to stat (more sampling holes or larger ones) or reduce heat loss in pipe system to stat (this seems like it would be less of an issue in summer, but when you are just cooling something a few degrees, even 150 F air from a radiator will have some cooling). Or wrap stat in some kind of insulation.
Do you have an IR thermometer that could measure the temp on case of stat, hoses nearby, etc?
BTW, D1 and D2 have same water pump, and my D1 sports a used pump form a D2. And I drive down the road 2000 rpm with coolant temp on scanner at about 2-3 F above number stamped on the stat. So with a 160, that is 162 - 163. A 180 yields 180 - 183.
Last edited by Savannah Buzz; 12-14-2011 at 04:34 AM.
#16
12-14-2011, 12:06 PM
Recovery Vehicle
No IR thermometer but will see if any of my friends have it. With that extra sensor, it would make sense I don't have one of those either. It said it would have a code if the difference (when conditions were met) between that and the other sensor was too great. When I put the new/defective t-stat in that never opened and temps went up quickly, I had no codes.
#17
12-14-2011, 01:27 PM
Recovery Vehicle
I got a new thermo, new brass impeller waterpump, belt, flush w new coolant an additive, and I get the same temps as you pretty much to the tee. ive heard people it normal, ive heard people say its hot.
but i dont like that the thermo is wide open in just idle and low road condition... above 40mph even in summer there should be enough airflow to keep the thing cool...especially with a fan pulling air the entire time at low speeds, and its a baby v8 and no thoroughbred thats for sure. god forbid i ever had to drive up an extended hill or try to tow something, that leaves NO reserve heating capacity. dunno if its just ****ty design (like everything else on these trucks haha) or some other gremlin thats never been resolved.
but i dont like that the thermo is wide open in just idle and low road condition... above 40mph even in summer there should be enough airflow to keep the thing cool...especially with a fan pulling air the entire time at low speeds, and its a baby v8 and no thoroughbred thats for sure. god forbid i ever had to drive up an extended hill or try to tow something, that leaves NO reserve heating capacity. dunno if its just ****ty design (like everything else on these trucks haha) or some other gremlin thats never been resolved.
#18
12-14-2011, 01:39 PM
Super Moderator
IMHO it is a design gremlin. The stat specs in RAVE engine management say it starts to open at 180, and full open at 204. That would equal a generic 180 GMC/Chevy stat. Which I have in my D1, with a water pump from a D2. And I roll down the road at about 2000 rpm and 182 - 183 F. I'm with you, it runs warm. May be the water to make it hot to open is low flow because of those little holes, and we need more holes. Maybe that sample water cools off in the pipe/hose/tee fittings and juist does not warm the stat enough to open it all the way. Could put some pipe wrap on for a test. In a D1, the stat is like two inches from the coolant temp sensor. Some guys have done a little re-plumbing and put a regular Chevy stat in a housing in the hose.
#19
12-14-2011, 11:44 PM
Recovery Vehicle
I hear people say both too kodiak. Honestly, if the fixes I'm looking to do now don't do anything, there is nothing else to do. Drive it until it blows up. And you know what, I will go out and get another one because I love these stupid things! I've driven it a year with those same temps (just didn't know it until recently with the Ultra Gauge), and it never overheated once, never had to add a drop of coolant and never and codes/issues. I sat in traffic this summer during the 105 degree heat wave going from NJ to Long Island through NYC and she was fine. I will do what I can to fix it, but after I do the final couple things there is NOTHING left to do. Everything in the system, sans the heater core, will be 100% new.
#20
12-15-2011, 04:40 AM
Super Moderator
Gentlemen, please look thru this post, it details how to install a few parts and drop the temps to the 180's, https://landroverforums.com/forum/di...ine+thermostat
The "cold water rush will hurt a liner" would also be mitigated by having a bleed hole in the stat, so a 1/8 inch trickle is always moving through, plus eliminate any air pocket build up.
IMHO some modification of the existing stat more holes, insulation) might yield similar results.
The "cold water rush will hurt a liner" would also be mitigated by having a bleed hole in the stat, so a 1/8 inch trickle is always moving through, plus eliminate any air pocket build up.
IMHO some modification of the existing stat more holes, insulation) might yield similar results.