Hey guys I have a 2009 320D with 2900hrs on it. It's been a great machine with really no issues other then these. The coolant just about always stays at 160f-165f which I think is a little on the low end. I blocked the radiator off today as it was just at the freezing mark to see if this would make a difference and it stayed the same. In the summer it runs the exact same Temps unless I really work it but the second I stop it rapidly shoots back down. Could this be a thermostat issue? The other issue is hydraulic temp. Cat has come out says nothing is wrong. I'm concerned it's getting to hot. On the computer it doesn't take much to get it over 85 celcius. Not in the red but then I let it cool down. Should I not be able to work this this all day in the summer without the hydraulic staying at the half way mark. Sorry for the long post just trying to relay as much info
Well first the s/n prefix would help as there is about 100 320d s/n but it appears most if not all come with a 160 f thermostat so your operating temp is bang on. As for the hyd temp at 85 c =185 F it is by no means "hot" so yes warmer than the engine but by no means hot. Why are you concerned ?
Loads of info about the problem symptoms but no Serial Number ....... with the S/N comes a part number for the thermostat and from that P/N comes the spec of said theromostat ......... easy peasy. Regarding your hydraulic oil temperature 85 DegC is just nicely warm IMHO. If you'd said 95 DegC I'd have been getting worried. Is 85 DegC equivalent to about half scale on your hydraulic temperature gauge..? Have you pressure washed the radiator/hydraulic oil cooler package recently..? Is it part of your regular maintenance schedule..? because if it isn't it ought to be.
Hey thanks for the fast reply. The serial number is PHX01510. I was under the impression that a operating temp of closer to 190f was more average. As for the hydraulic 85 is as high as I will let it get on a hot day and working it hard I know it will go higher I just don't want to push it. I power wash the rad on a weekly basis and keep those screens squeeze clean. When it hits 85 DegC that puts it at two bars over half. Maybe I'm being a bit to concerned with these Temps I just thought other 320d I ran, ran a little cooler on hydraulic side and warmer on engine. Thanks
I should add when the mechanic came out he said it was set up for low ambient temperature. So he changed the fan settings and now when hydraulic hits 77 DegC the fan kicks up a notch. I also had a few holes cut in the door as it was perfectly sealed before
I'm wondering if the 160 degree thermostat has anything to do with the EPA emission requirements. I remember back a few years ago all the cars had to have a 195 degree thermostat to raise firing and exhaust temperatures. High firing temperatures in a diesel engine cause the formations of NOX. I also remember being told that cold operation on a diesel engine promotes the formation of acids which is the real reason for wear on pistons, rings and cylinder liners. Maybe that is part of the reason for the move to ultra low sulfur fuels. As for the hydraulic oil temperature I always like them in the 150 degree F range. What kind of attachments are you running on your machine? Rotating items with continuous flow will heat things up pretty quickly. Nige has the most common cause of overheating in excavators nailed. Dirt between the hydraulic oil cooler and the radiator. Make sure it is cleaned out completely.
I'm going to look into the technical specs of the thermostat but meantime another question. The hydraulic oil cooler is sandwiched tight to the back of the radiator and is almost impossible to clean from the outside or inside. The only solution is to remove the complete cooling package and separate the cooler from the radiator. You might be rather surprised at the amount of contamination in between the two that severely restricts air flow. I'm not sure about cutting extra holes. Why not post a photo showing what you've done so that an informed opinion can be given..?
sorry it's not a close up.but this is a pic of the holes I had cut in it. Also the the left of the 320 sticker there are two. Just hard to see
Well the first thing I found regarding the thermostat is that it was updated in 2009 to a "more robust" (Cat's words not mine) part. As your particular machine was manufactured in 2008 you do not have this upgrade which came from S/N PHX02166 onwards. So I suggest that you might consider changing the existing 5I-8010 temperature regulator for a 324-4128. To make the change will also require 2 gaskets - 1 each of 5I-7735 & 294-1780. Now on to the specification. It starts to open at 71 DegC (160 DegF) and should be fully open by 85 DegC (185 DegF). So if your machine is only running normally at around 75 DegC I would suspect the temperature regulator may possibly have stuck wide open. Looking at the layout of the hydraulic oil cooler and the radiator in your machine you have the side-by-side setup instead of the piggy-backed one in front of the other setup that I've seen on other machines which is close to impossible to clean properly. However the extent of the plastic shrouding around the fan means that whichever design of cooling package you have it's almost impossible to clean it thoroughly without some disassembly. If you can spare the time and effort I think I'd still consider pulling the cooling package and doing a spring-clean job on it just to reassure yourself that the coolers are working correctly. As a last suggestion try getting hold of an infra-red temperature gun and check the temperature of the hydraulic oil at the same location as the temperature sender. The sender is mounted on the hydraulic tank next to the pilot filter assembly. Look for wire #491 Pink which is one of the two wires that are connected to the sender. The other is #235 Black but that's a common ground for multiple functions. If there is a major difference between what the sender reads on the monitor panel and what the temp gun reads you could have a bad sender.
Ok I will order those parts. I didn't have a look but Is the thermostat easily accessible from the engine bay? Work will be slowing down shortly and when it does I'll bring the machine in our shop and clean the cooler and take it apart. I went in service mode today and the fan is set to high ambient temperature low noise. It won't let me change it but I think I will have the mechanic change it to high ambient temperature. If I change to the upgraded thermostat what temp should the coolant be operating at? Thanks again for all the info. Also by sending unit did you mean the temperature sensor for hydraulic? If so I changed that out recently. I did notice today in service mode it said ambient temperature was stuck on 74DegC. Not sure if that affects anything.
I just called aND I can get all those parts here by Tuesday morning. Is there just one thermostat? How simple of a job??
See below, it's fairly simple. there is only 1 thermostat. Loosen clip #15 and slide hose #9 off the thermostat housing. You will probably also have to remove one end of the large hose that fits into the top of housing #1. Remove the 3 bolts #12 and lift off the top housing, the thermostat is right underneath it. You will be replacing #10, 11, & 16. You'll probably lose a bit of coolant in the process.
I changed the thermostat both had 160 stamped in the bottom so coolant is still running at 160. I still feel it's too cool but if that's how it came from cat I'll leave it. As far as the hydraulic I'll give it a good clean this winter and go from there. What are other guys seeing for hydraulic Temps in the summer?