| Author | Message | ||
| Doug J (Doug_j)
Registered Member Username: Doug_j Post Number: 17 Registered: 8-2006 Posted From: 207.199.206.169 Rating: N/A |
"The cooling system has been completly gone through and road tested on 3 different occasions, there are no thermostats in it at present as they had been acting up and the mechanic did not reinstall them" This is a sentence from the owner of a bus I have inquired about. Does this make sense to any of you that are more mechanically inclined than I am? What effects will this have on the "systems"? | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 255 Registered: 8-2006 Posted From: 74.32.81.73 Rating: N/A |
Doug, can you tell us what engine,thermostats serve to heat the engine up faster,keep the engine at the right temp for better combustion of the fuel and to allow the coolant to flow at a rate for the fan and radiator to do its job most of the time when people leave out the thermostats they are trying to cover up another problem.others will chime in on this I hope but this is my understanding why they are a must on diesel engines (Message edited by luvrbus on January 12, 2008) (Message edited by luvrbus on January 12, 2008) (Message edited by luvrbus on January 12, 2008) | ||
| steve gaines (Kysteve)
Registered Member Username: Kysteve Post Number: 127 Registered: 12-2006 Posted From: 74.140.165.225 Rating: N/A |
(Message edited by kysteve on January 12, 2008) | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 816 Registered: 10-2003 Posted From: 71.58.48.5 Rating: N/A |
"Completely"? Thermostats rarely act up. They either work, stick open or stick closed. The mechanic either isn't very experienced or owner didn't want to spend the amount of money required to fix the problem correctly.Good chance the radiator needs cleaned/ replaced. Of course, there could be other problems- bigger engine install or larger injectors/ turbo, etc.What model and make of coach is it? | ||
| Doug J (Doug_j)
Registered Member Username: Doug_j Post Number: 18 Registered: 8-2006 Posted From: 207.199.206.169 Rating: N/A |
This is in a 62 4106--8V71 | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 817 Registered: 10-2003 Posted From: 71.58.48.5 Rating: N/A |
What kind of condition does the exterior sides of the radiator appear to be in? Fins all straight and intact? Does it look like it was recently removed for internal cleaning or been recored? | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 571 Registered: 11-2005 Posted From: 208.54.200.70 Rating: N/A |
If the thermostats are removed and the engine runs at normal temp it will most likely run too hot in hot weather. A normal cooling system on a DD will never warm up to normal without a thermostat that blocks off the radiator. | ||
| Laryn Christley (Barn_owl)
Registered Member Username: Barn_owl Post Number: 104 Registered: 10-2006 Posted From: 70.110.13.133 Rating: N/A |
Gus, Your second sentence I understand, but the first seems to contradict it. If it never warms up without them, then how will it run too hot in hot weather without them? I need everything spelled out I suppose. Thanks | ||
| John and Barb Tesser (Bigrigger)
Registered Member Username: Bigrigger Post Number: 48 Registered: 9-2007 Posted From: 24.197.246.104 Rating: N/A |
I don't want to answer for Gus, but I took it to mean that if the engine is running at normal temps with no thermostats, then there is some other problem with the cooling system and that will cause it to run too hot when the amibient air temp is higher. Without thermostats, the engine should never get up to normal temperature, or at least run on the cool side of normal. Radiators aren't cheap, but are certainly available if that is what you need. My 5C with a 6v71 takes two radiators. I bought a used one from Luke and had them take it and get it recored and it was something north of a twelve hundred dollars with shipping. | ||
| Doug J (Doug_j)
Registered Member Username: Doug_j Post Number: 19 Registered: 8-2006 Posted From: 207.199.206.169 Rating: N/A |
I am 650 plus miles away from the coach, so no info on the radiator. I wanted to ask some of you guys for opinions before I make the trip to look at the bus. | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 822 Registered: 10-2003 Posted From: 71.58.48.5 Rating: N/A |
With no thermostats the temp will be on the cool side UNLESS there is a mechanical problem or the radiator is partially plugged. The thermostats open and close on a normal system to get up to operating temperature quickly, and then open and close as needed to maintain that.A significantly restricted radiator or internal engine problems, such as a cracked head/ heads can cause noticeable swings in temperature as the thermostats try to maintain temperature. This is what " acting up" can be the resulting symtom.BTW, the compression bubbles from a cracked head or failed head / gasket seal will accumulate near the thermostat, insulating it from the hot coolant till it finally gets hot enough to finally open it. You could take oil and coolant coolant samples to one of the testing companies that trucking companies use to see if the engine has expensive damage. Do a search - they usually provide kits with instructions. If there are problems found, it could be a good bargaining chip or a reason to walk away. If you read here a lot, you can see how many thousands you can get into for major engine repairs. Detroits don't tolerate overheating or any diesel for that matter. | ||
| Doug J (Doug_j)
Registered Member Username: Doug_j Post Number: 20 Registered: 8-2006 Posted From: 207.199.206.169 Rating: N/A |
We are looking for our 3rd bus, and that is why I'm asking here. We all know it doesn't take too much to start digging into the back pocket. The guy has receipts for all work done through out his ownership, but that doesn't mean he's had enough and is trying to dump a money pit. | ||
| Laryn Christley (Barn_owl)
Registered Member Username: Barn_owl Post Number: 105 Registered: 10-2006 Posted From: 70.110.13.133 Rating: N/A |
OK, got it. The light bulb came back on. LOL Thanks (Message edited by barn_owl on January 13, 2008) | ||
| Bruce Henderson (Oonrahnjay)
Registered Member Username: Oonrahnjay Post Number: 212 Registered: 8-2004 Posted From: 69.143.41.243 Rating: N/A |
Doug J wrote: "We are looking for our 3rd bus, and that is why I'm asking here" Doug, this one is making my $$$$$-sensor tingle! "It's OK, it's just the thermostat" is a phrase that's gotten a lot of people in trouble! | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 823 Registered: 10-2003 Posted From: 71.58.48.5 Rating: N/A |
Let's see 600 miles.... that could be Fred's coach- BEWARE air system is full of oil and moisture!!!!! Just kidding Fred.  | ||
| Douglas Wotring (Tekebird)
Registered Member Username: Tekebird Post Number: 292 Registered: 10-2004 Posted From: 71.59.75.212 Rating: N/A |
Simple.....if the guy does not have tstats in his engine don;t buy the bus. t stats are cheap and he already paid the labor to take them out. clear evidence of a poorly or non maintained bus. unless you like working on other peoples problems.....or the price is super spectacular. Run away | ||
| Jim & Linda Callaghan (Jimc)
Registered Member Username: Jimc Post Number: 47 Registered: 2-2004 Posted From: 75.210.52.219 Rating: N/A |
Another problem with running with no thermstats is that in warm weather, or on a long pull, the engine will still overheat. one function of a Tstat is to keep the water in the radiator long enough to let it cool prior to getting to the motor. Its very common in street rods, the owner has too small of a radiator and they pull the Tstat to gain what they feel is cooler water, but in fact it still gets hot becasue it cant cool off long enough in the radiator. | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 347 Registered: 8-2006 Posted From: 207.231.75.253 Rating: N/A |
Sorry, But "water not staying in a radiator long enough to cool off" is an old wives tale, not to mention that it would then stay in the engine too long, and get too hot. What actually happens, is that the faster the flow, the more total heat is removed, although the temperature drop from inlet to outlet is reduced. This is published data by all of the hydronic heating manufacturers, in rating their units. The bigger the electric water pump, the faster the flow, and the higher the BTU output. Now, if you take a BYPASS thermostat (which works backwards to most thermostats) out of an OLD Detroit, and some others, it will overheat, because coolant bypasses the radiator, and returns to the engine hot. Stop for a minute and think, (don't forget to start again!) why did the original mech pull the stats? Couldn't be because the bus was having a heating problem to start with could it? Where is a thermostat located? In the hot water outlet of the heads, where it sees the hottest water, right? What does the stat do when it sees warm water? It starts to open, and as the water temperature increases, it opens further. IF the water went thru the radiator too fast, didn't cool off, came back to the engine hot, then it would be REALLY hot when it got to the thermostat the second time? G | ||
| Larry D Baker (Lbaker4106)
Registered Member Username: Lbaker4106 Post Number: 73 Registered: 5-2005 Posted From: 207.69.137.10 Rating: N/A |
Beware!!! My 61 4106 with a 8v71 had overheating problems over the summer. At a rally I took them out but I didn't get very far. My thermostats were bypass type and with them out the coolant was short cycling back to the engine and not cooling. The final problem was cracked heads which allowed the exhaust to over pressurize the coolant sysem and finally push coolant out the overflow. I suspect the bus may have engine problems. Larry 4106 |