Okay, decided this needed to be in it's own topic.
I've got a '87 Chevy P-30 454 pulling my 15K lb 33ft GV.
Engine has 45K miles on it.
It gets hot on hills. All of them. Even little ones.
If the hill goes on for more than 5-8 miles (depending on grade)... the radiator fluid boils over and the engine loses power and we have to shut it off and pull off to the side and let the engine cool. And we have to manually return fluid to the radiator because our tank and cap do not have a return line.
Coolant System details:-Two electric fans pushing air into front of radiator
-Big 7 blade fan pulling air through radiator from back side.
-Fan clutch has been checked (it's not bad, but will need to be replaced eventually it's close to being worn, but it's not there yet and functions as it's supposed to - had mechanic check it)
-Thermostat has been replaced with a brand new 190 degree one.
-Radiator has been flushed by qualified mechanic. All fluid was clear. New fluid is in the radiator.
-The dash gauge is digital and does not provide an exact temperature... just a normal range, and hot range, and a boiled over your coach is gonna explode range (lol... this is the red section).
-I've added a mister system in front of the radiator that I turn on when going over hills. 6 Misters. This seems to have solved the problem for all but longer hills.
-On flat ground the digital gauge keeps very steady in the center of the temp range. Once you start climbing any hill it starts going to the right side. The longer the hill is, the hotter it gets. If the hill is long enough... it always overheats and boils over. As soon as you get over the top of the hill, it starts dropping back to the center very quickly.
Things I've fixed/replaced already (just in case they have an impact on coolant system
-New starter
-New alternator
-New plugs, cap, wires, and rotor
-New fuel pump
-New fuel filter
-New air filter
-Reattached some vacuum lines that were off
-New vacuum line filters in air intake box (called Emission control filters - nappa prt #2995)
What other details or pictures would you guys need to help me diagnose and fix my overheating issue? I'll get them taken and added as soon as I can.
-New fusible links in ignition lines
-New neutral safety switch
-New ignition switch
Just an FYI - I'm good with a wrench and with fixing things... but engines aren't my forte... computer are. Diagnostics processes are about the same (my brother is a mechanic we compare notes all the time). What that means is I can take things apart and put them back together (and be anal retentive about it and make sure it's done right) with the best of them... but a lot the things on an engine I'm not familiar with the jargon or the purpose of a thing just by hearing the name. So explanations are super helpful. As are pointers on where to look for a thing.
Some questions
@Caflashbob asked in my renovation thread:
"What you think is heating up maybe normal? Not coolant loss although." - Before you get to the red line... there is no coolant loss. After you hit the red line, it's boiled over and filling the reserve tank. There is no return line. Once it's hit this point, the engine experience power loss and you must pull over and let it cool before it'll drive again.
"Crud in core? Flush radiator?" - had it flushed by a mechanic. They showed me the fluid that came out of it. He said it was clean and looked good to him.
"Slipping water pump drive belt?
Corroded water pump impeller?
Defective sending gauge?
Timing too advanced?
Distributor worn?" - Got any pointers on checking to see if any of these are my issue?
"Bad dash gauge?
Poor dash ground for gauge? "-The dash closer is all one piece and all digital. The radiator temp moves pretty consistently, so I don't think it's bad. But it could be. Not sure how I'd check it?
"Need new cap?" - I probably do need a new cap and tank since I have no return line. Could that be all it takes?
This may not be the case, somewhere way back in my memory there was one of engines that had two different water pumps, on the surface they looked alike but one had a deeper impeller. Just for what it worth.
The same line that goes to the overflow returns the fluid when it cools down, if you have the right radiator cap and the overflow hose goes to the bottom of the overflow tank. Too much retard overheats, too much advance detonates. Check the timing. There were 2 different water pumps one with a long nose and one with a short one. The 89 should have the long one and it should get close to the radiator. There has been no mention of a shroud it should have one they make a big difference in airflow. A new water pump from one of the lifetime warrantee places wouldn't hurt, eventually they will leak.
Can you look thru the radiator opening and actually see the tubes to make sure they are not plugged?Some old radiators used
to have to get "rodded out" a procedure where the radiator is disassembled and rods are pushed thru the tubes to clean.If it were
mine I would put a 0w30 or 0w40 Amsoil in and a bypass filter the bypass will give you maybe 2 quarts more oil.
Two things I have personally experienced that caused overheating back when I was involved with stock cars.
1. Engine fan was too close to the radiator. Took the spacer off the front of the water pump behind the fan and the engine ran cool after that.
Check if your fan is about 2" away from the radiator.
2. The bottom radiator hose normally had a wire inside the hose to keep it from collapsing from water pump suction. The wire had broken into pieces and choked down coolant flow. You might want to try holding the revs up on the engine a bit and have someone watching the bottom hose for collapsing. Wouldn't hurt to check the top hose also.
Look at a website called Griffin radiators,if you can fit a bigger radiator in place of yours they will have one,that may be an option.
Get a temp gun and take temps of the radiator and shut that electric fan off you may have too much air flowing too fast to
absorb heat,is worth a try.
You might take an infrared thermometer and shoot different parts of the radiator to see if it is fairly uniform. If a significant percentage of the core tubes are constricted, that would reduce cooling capacity. Regardless of what the mechanic tells you, I would investigate options for replacing the radiator with one that has more cooling capacity, possibly more rows, maybe an aluminum one. I had a 454 Suburban that was tending to overheat, and though it ran great and never experienced a lack of power during those episodes, it was idling at a stop light and just died. I pulled the heads off and discovered a huge crack in the cylinder wall. This happened as I was attempting to find the cause and fixing this and that (new water pump, new thermostat, etc.). Kind of soured me on Chevy big blocks for life... anyway, don't let it go. I am glad you are trying to be proactive about the issue.
Don
You can flow water too fast to throw off heat, but not air. Just because the water was clear when flushed doesn't mean there is good flow. A good way to test flow is to fill the radiator up with water with the bottom outlet plugged. then release the plug on the bottom and the water should rush out immediately. If it doesn't, get the radiator rodded out as posted above or the core replaced.
Took my ford econoline to quartsite in Jan this year. overheated most of the trip. First fix was radiator cap. Second and last was when the mech in Van Horn, Tx showed me the stopped up cores in the radiator and we put a new one in. Been just fine since.
Jim
Something those 454s were infamous for were the exhaust manifold of poor design. They were called "B.B.Q. specials". I think it was Banks that made headers with better flow & cooling. ^.^d
@craneman Here's a quick video showing the radiator tank and cap. There is no return: YouTube (https://youtu.be/GNA_E2UCsxs)
If the radiator cap will not hold the pressure the coolant will boil and boil out . A new cap could help be sure the hoses and clamps will hold the pressure too. Be careful coolant under pressure can be very hot and dangerous.
Wantabe
The video doesn't work.
But as I said if you have an overflow hose going to a tank or bottle the same hose returns the coolant.
Are you saying you don't have a hose coming out of the fill neck?
Fixed the video, you should be able to see it now.
The tube should go to the bottom of the expansion tank and below the level all the time.
Engine gets hot, liquid in radiator expands, flows into overflow tank.
Engine cools off, liquid in radiator contracts producing a slight vacuum, which sucks the liquid out of the overflow tank back into radiator.
As long as liquid level in overflow tank does not get below the end of tube (with engine cold), you should always have a "full" radiator.
Tube goes to bottom of tank, there may or may not be a little weight/filter thingy on bottom end of tube, like this:
Check the engine timing----if it is off by much, it will overheat. You might also have the distributor vacuum advance checked. Another issue can be high exhaust back pressure. Maybe someone replaced the muffler with the wrong one.
Do you have a single or dual core radiator?
Like has been mentioned before very easy to make this into a coolant recovery, need to have a coolant recovery cap and you already have the recovery bottle, just make sure the hose from the radiator goes to the bottom of the tank. I would also put in a 180 thermostat.
Yup, mine looks like the wrong one. Can I buy the extension tube thingy that goes to the bottom of the tank? What would I even ask for at the auto parts store?
How would I find that out?
With a 30 year old coach you will have to learn how to improvise. Any piece of tubing that will fit tightly into expansion tank cap will work. If flexible hose or tubing, a stainless nut and a tie wrap will weight it down to keep the hose in the bottom of the tank.
After checking everything, sounds like a radiator rebuild/replace. Where it me I would look at one of the custom race radiator builders. Expensive but once and done. You may also check and make sure you don't have any exhaust getting in the cooling system (leaking head gaskets) you can get the check kit from NAPA or just use your nose. Has this been a long time issue or did it just start? Going to need to find the problem soon or it will not be good.
How thick is your radiator? I think a single core would be around an inch or Inch and a half and dual core would be twice that. More tubes and more fins to transfer heat.
Definitely agree it's time to have radiator overhauled. You also need to pressure check your cooling system. Since your problems are so bad, I would remove the water pump and inspect the impeller for eroded or missing vanes. When you had radiator flushed, did you flush the engine also? When you remove water pump, inspect the engine for buildup.
Is this coach rear engine or front? Maybe add independent tranny cooler with fan. If rear Engine use the heater hose lines and add a radiator at the front with fans from a salvaged 4 cylinder car. Check the seat in the radiator neck where the cap rubber valve seals too. How much do you weigh? if irc you emptied your house or apartment into the coach.
I build single cylinder dirt bike four stroke engines and their carbs.
Yours sounds lean. Hot. Less power?. Good gas mileage?.
Rebuild carb?. Have someone check the air to fuel ratio,
Too much advance on timing. Or lean.
Any chance exhaust blocked?
Building on phred's suggestion, you could also consider fitting a external
engine oil cooler. These are commonly used on hard-working engines in all sorts of venues. Engine oil doesn't just lubricate - it also helps cool the engine. A good quality oil cooler would be size matched to the engine displacement, and controlled by a thermostatic valve that only opens when a certain oil temp is reached. There are many types/configurations.
Links below to some websites for more info:
Guide To Engine & Transmission Oil Coolers | Medium Duty Work Truck Info (http://www.hardworkingtrucks.com/engine-oil-coolers/)
Derale Performance | The leader in performance cooling! (https://derale.com)
http://www.haydenauto.com/featured%20products-transmission%20and%20engine%20oil%20coolers/content.aspx
Like Bob says. 1) Check timing , reduce the lead 3 degrees. regardless of where it is.
2) Oil cooler may drop it 5 *
3) Synthetic oil will drop it a couple. Plus wont burn/coke the oil.
4) Check or change the water pump . often they look like new but the fins are missing or reduced.
5) The rad coolant return line should show 20 or more * of heat loss. The headers and manifolds can radiate heat back into the coolant hose if they are close. The IR heat gun will show if that happens.
6) Add or check for rad shrouds being in place. Plug the gaps around the radiator .
My P 30 put down many miles without getting overly hot @ 18K #
You need some fans like these: ELECTRIFYING THE FUTURE AT PREVOST | Prevost (https://www.prevostcar.com/news-and-media/media-center/news/electrifying-future-prevost)
Is there anything that can be added to coolant to improve heat transfer?
I think proper mix of water and antifreeze is important for heat transfer.
I run a 60% water 40% delo ELC which gives a greatly improved heat trqnsfer over normal green coolant and over a 50/50 elc mix. Lowers the freeze protection to -15f but I know my engine will never see those temps in my climate or anywhere I will ever go. Really helped with temps creeping up on long hill climbs.
I think you have many issues, most likely would benefit from a new larger radiator and clean core, even if flushing produced clean water the tubes could be clogged preventing the flush from reaching them. You need a methodical troubleshoot by a pro to get this thing going! Even timing or fuel mix could be the cause. Clogged secondaries causing a lean condition climbing hills? Bad timing advance? Bad base timing? So many possibilities.
Water wetter, reduces surface tension of water molecules so they are more easily stripped from Surfaces
I think you've solved your own problem. If you don't have coolant returning to the radiator from the expansion tank it will over heat from loss of coolant. Fix that first and add a new radiator cap just for the helluvit cuz they're cheap. And the 180 thermostat for a 454 as previously mentioned. Also cheap.
Before you spend a lot of money on stuff that may not need replacing, take the thermostat out, go for a drive up some hills and see if that fixes the problem. Today's thermostats are junk even when brand new. If the engine doesn't overheat with the thermostat removed, buy a bunch of new thermostats, take them home and put them all in a pot of water on the stove and boil them. Watch carefully to see which thermostat opens first. Install that thermostat and get rid of the others... Please don't return them to the parts store for some other poor unfortunate person to install in their engine! :))
That 454 does not like being so hot that it doesn't run. Cylinders will get egg shaped, so need to fix it sooner than later or you will be replacing the engine and that is a real problem on a front engine chevy chassis.
Don't run with no thermostat. The water moves too fast for adequate heat transfer. Cut the venter out of the thermostat so that the outer disc is intact. This is the required amount of fluid restriction. Even on race cars with out the thermostat we either cut a thermostat apart or ordered a restrictor in.
Another option is an electric waterpump. Pump speeds up and slows down based on the temp sent to control module. We are still experimenting with it in the new race car.
Bottom line I had an 89 P30 454 SOB nothing special done to it, towing a 20' trailer full of motorcycles all stock never got close to running hot. Got to be something wrong. Gm designed it to work without all the extra fans and so on. JMHO
Whenever I have a thermostat fail I remove it and don't replace it until winter. I've never had an engine overheat without a thermostat. Quite the contrary, it takes forever for the engine to warm up properly, if it ever does. That's the major danger to running with no thermostat, that the engine won't get warm enough to boil off contaminants and sludge will start to build up as a result... but he just needs to remove the thermostat for testing and then find a working thermostat to replace it with... (good luck) ...and if you have a thermostat that works don't ever replace it because you'll have a tough time finding another one that works properly. Go get a few from the local parts store and boil them on the stove to see for yourself how poor the quality is today.
Hmmm, neither have I...
BBeane, did your SOB have an auxiliary oil cooler?
For the trans only( turbo 400), and it was likely aftermarket. Got the old thing on a trade it was a National Dolphin, ran the stuff out of it for 2 years.
Say what? Better examine the proven eqautions, in typical non overheating mode this may appear to hold true as the delta temps go down on one side. Total bs when overheating.
Install an intake manifold vacuum guage.
Check for timing chain stretch.
The vacuum guage will help with any diagnoss of timing / fueling issues.
Is this a carbureted or throttle body engine?
Do we know if this is an all of a sudden issue, or a long term problem? Makes a difference in where to start looking.
The only 454 I ever liked, was a buddy who had it in his 1/2 ton pickup with stick shift. You did not want to race that guy! ^.^d
Driving while overheating until the engine loses power is a sure way to have to replace it. Have you checked for products of combustion the the coolant? The symptoms you describe are exactly the same for a improperly torqued head or a damaged head gasket. I bought a 3.4 Jaguar with a custom rebuilt 327 in it. The previous owner spent a fortune with new radiators, etc but it still overheated at anything above an idle. I just torqued the engine to specs and then drove it for years. But, I never let it get a hot as you describe.
A radiator shop can check for products of combustion or you can easily do it yourself with this kit: Amazon.com: UVIEW 560000 Combustion Leak Tester: Automotive (https://www.amazon.com/UVIEW-560000-Combustion-Leak-Tester/dp/B000NPDL76)
Pierce
That coach has a carb.
Seems as the OP is missing.
Probably overwhelmed with all the suggestions. Remember he is full timing with kids.
op is new to this unit so likely doesn't have a history on how long its been overheating. he could be fighting old damage.
as for the water restrictor we run 454s punched to 468 on the circle tracks and through testing as well as testing the engine builder has done no restrictor runs hotter. some where I used to have a gm tech bulletin about it too but these days I cant find a receipt from last week let alone a bulletin as old as I am.
you have a lot of suggestions to go through, really it all comes down to doing a complete step by step check of the whole system. be sure to make sure you are actually getting heat transfer check water temp into and out of the engine and the radiator. make sure the water is actually cooling in the rad. over heating could have caused the rad tubes to swell. they can swell to the point of touching each other which means no airflow through the rad and no cooling of the fluid.
...trust me, just take that new thermostat out and see if that fixes it instead of spending tons of time and money on stuff that may not need to be replaced ...removing the thermostat is the first step every mechanic I know takes if he can't find anything obviously wrong ...if that doesn't work start going through this list
I'm more than happy to try this, I'm curious though... what is taking the thermostat out going to do? Will that make the Cooling system run all the time? Or will the radiator flow constantly. I get that it may be bad... Will anything else break by not having it in there?
NM found your answer... Lol. :)
Bought the coach in Texas... drove it all the way to Vegas and it didn't overheat.. cause we hit no real hills. Went out of vegas and up the first big hill there and that was the first time it went over the Too Hot side of the meter. Started discovereing issues.. like not having a return pipe on the radiator tank. So it's likely a long term issue.
We were just out of Cell service area for a few days. Not missing totally. :D
And the suggestions are awesome. I have a whole list and I'm taking them back to my brother (who's a hobby mechanic) this next week.
We are definitely adding the radiator tank return line. Gonna test the Thermostat as suggested. Then I'll have to take the rest of the suggestion and run them by him to see what I should check next.
@All - Thank you all for the amazing suggestions. This is a killer community. I don't know what buys of SOB's do when their coaches have problems, lol.
Anyways, I've got a lot of stuff to look at and looks like I have an excuse to add some new tools to my tool kit... and I never complain about that.
Also, another Foretraveler has offered my the fully functional radiator out of his p-30. So i'll have some known good parts to put in.
I'll report back here when I have updates.
Also - for those of you worried... the coach has been running much cooler since I installed the Mister system. Drove over several hills today and didn't get across the "too hot" line. Still goes over the center line though and gets warmer. I know this is a stop-gap measure. But it's not OVERheating on normal hills anymore. I still think we'd boil over on big/long grades though.
The overflow return will not affect your heating issue. It will affect having to add coolant as the overflow only returns coolant to the radiator after the engine cools down. My personal opinion which I use, is make sure the radiator has flow through it first, then if it is ok go through with the other suggestions above. I have worked on several big block trucks and motorhomes and they would run up hills without over heating.
UPDATE on this.
I finally solved this issue. In the end it was the fan clutch that the first radiator shop told me was alright. Talked to another radiator guy... he said he was 90% sure my symptoms were fan clutch related. So I replaced it. Took all of 30 minutes to do and cost lets than 70$.
Coach stays cool now... even on bigger hills. In normal driving the coach stays to the left of center of my temp meter. Used to stay right of center. And on hills it stays center and occasionally dances to the right of center. It used to go straight to just below hot and dance with the hot line... and if the hill was long enough.. it'd overheat.
The fan clutch engages all the time now. Sounds like a jet taking off... and it's the most glorious sound on the road. It's the sound of my cooling system working well.
Also got a new radiator cap and got the fluid return line setup and working.
Thanks everyone for all your help!
Glad you got it resolved, so happy trails.