LUVTruck.com

Hey all,
I am new to the website, but have reading as much as I can from previous posts about my overheating engine problem. First off, thank you all for all your contributions to this site. I have already learned a LOT!

So, I have a 2WD '79 Luv (blue) that I bought in WV a few years ago and three manuals for it, Haynes, Clymer, and Chilton. I am new to working on vehicles, but have a lot of fun doing it! I replaced the clutch last year. I have driven Dottie (her name) about 23,000 miles since, to Maine and Canada, down to Florida, out to Arizona (where I lived for a couple years), to San Francisco, and now to the DC area where I am living. About 8 months ago in AZ, it overheated for the first time. I added coolant and it was fine for another 5 or 6 months (side note, my temp needle (stock temp gauge) falls directly in the gap between the upper broken white line at normal operating temp (about 10:00). On my 2500 mile trip to DC in Dec, it overheated again in Oklahoma. I added more coolant (which had boiled out) and some of that aluminum powder. It overheated a couple more times over the remaining 1500 miles or so, and I added coolant each time).

I found this site in January and started following your suggestions. First I replaced the thermostat. Sometimes, the needle would climb to within a half to a quarter inch of the H on the gauge before the thermostat would kick in and drop it down to normal. Sometimes the needle would travel about halfway to the H before climbing back down (normal, I figure). Whenever it would get close to the H, I would lose coolant because it boiled off. I'd let it cool down, add more, and go on my way. Next I replaced the water pump. It still behaved the same way, so I flushed the system with that Zerex stuff. Still had the same intermittent overheating. I figured before I spent money on a new radiator, I'd recheck the thermostat. I took out the new one, returned it to Advance, got a fresh new one, tested it on the stove (opened at 180 degrees), and put that in. Still had the same problems. I ran it without the thermostat and it took about 45 minutes of driving, but it overheated then too. I figure it has got to be the radiator. I bought a new radiator (http://www.outlawradiator.com $100 included shipping, best deal I could find). I installed that and by now I am suspecting that I have blown a head gasket in the whole process (I believe I had been losing coolant, though it was hard to tell what with draining it every week or so). No malted milkshake oil or foam at this point either though. It was around freezing outside at this point too, so it was hard to tell if the white smoke coming from the tailpipe was normal water vapor or if there was coolant mixed in too. I run the truck a few times with the new radiator and the needle gets to the edge of the upper white bar near the H. By this time, I check the oil again, and it is looking thin and discolored (milk chocolate like), and THE LEVEL HAS RISEN about 3/4 of an inch on the dipstick. I look in the valve cover, and there is some tan colored foam (and the coolant was low). So now I am pretty certain that the head gasket is blown and I am ready to put that in (I read many of your posts about how to do this properly, thanks!). I just now checked the compression (I figure good to do before I change the head gasket). I have never done this before, but this is what I got: spark plug chamber near the grill: 160, next 150, next 150, last (near firewall) 150. What order is that, 4,3,2,1 or 1,2,3,4??? The chamber that was 160 coated the spark plug with a small amount of oil (and also the compression tester end).

So at this point, I am still trying to figure out what is causing the overheating. I figure if the head gasket is blown bad enough, then I could lose a lot of coolant, and then the coolant level would be low and coolant being low can cause it to overheat. But I wasn't losing THAT much. Maybe a pint to a pint and a half after driving 45 minutes (from the reservoir, the radiator would still be full at the end of the trip!).

Any idea why she is still overheating with all those new parts? What is the next thing to try, replacing the head gasket? I don't want to replace it just to have it blow again.

Any thoughts would be appreciated.

Thanks!

PS Sorry for the long post, I figured more info is better than not enough!

It sounds like you're on the right track. Even though the compression check looks fairly constant, the gasket can leak from the water jacket to an oil passage. The milky-looking oil is a sure sign.
From your post, this repair shouldn't pose a problem for you. You need to get the head checked for cracks just to be safe and get it milled to get rid of any warpage. Good luck to you and welcome to the site!

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Previous setup: 4.1 Buick V-6/TH 350
Current setup: 400 Small Block Chevy V-8/TH 350
9" ford rear end/short bed/blue
What do Water, Electricity and Humans have in common... They all travel the path of least resistance.

I agree with BM, when you pull the head definitely at least get it checked for warpage. Good luck and welcome.

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Resident lurker

Thanks for the responses so far and the welcomes! This site rocks! I am going to change the head gasket this weekend. I will check the head for warpage. I'll try it first with a carpenters square as suggested in other posts and see how bad it looks. If it is warped I will take it to get milled. If there are cracks, will they be obvious, or is that only the sort of thing that a shop would see? Also, can this leaking head gasket be responsible for the overheating that I described even when the radiator stays full???

if you havent yet pulled the head to do the gasket, there is a test ya can do to check if there is a coolent leak into the engine, ya get a screw in fitting that fits into the spark plug hole, clamp it to a bit of air compressor hose, put a tap like valve in the middle and a fitting to attach to a compressor to the other end. with the cylinder at TDC screw the hose into the spark plug hole take the radiator cap off, slowly open the tap valve on the hose allowing the cylinder to fill with compressed air, do it slowly just incase it tries to crank the engine, if there is a leak the radiator will start to overflow.
i duno how good this description is but if ya have any questions plz ask

hope this helps

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I said no to drugs....But they just wouldn't listen!

No matter how good she looks, some other guy is sick and tired of putting up with her crap!

can a blown head gasket cause the engine to overheat?

Hell yes it can!!! After it burns all the water up and steams it out the tail pipe.

Sorry. I didn't have time to read the whole thing I just wanted to answer the topic question.

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OK, I'm over it. Where's the beer?

Noyz, thanks, thats a good trick I didn't know about! Unfortunately I don't have a compressor (and no friends in the area do). I will remember it for next time though. I am about 99.9% sure it is blown though because the oil level has risen and it is slightly discolored (more tan than it should be) (and lost some coolant).

Rondog, thanks too! My radiator was still full when it was overheating though.

Anyone out there know what can cause chronic overheating if the thermostat, water pump, radiator, and radiator cap are all new (and the radiator is full)? The head gasket is leaking coolant into the oil, but the radiator is full!

I have the valve cover off and am about to remove the head.

ive had the same problem with my luv, id be driving along and all of a sudden it would start to overheat rather quickly. it was mainly while doing highway driving so its reving quite high, but it also did it while stationary. i just blead the cooling system, and it seams to have fixed it. you may have an air lock causing a hot spot

try draining the coolant, when ya come to fill it, take off 1 heater hose, fill it up from the radiator till it comes out either the heater or the hose, when it does block it off with ya finger till it comes out of the other one, when ya know there is coolant coming out both ways, connect it back up. leave the radiator cap off and run it till the thermostat opens and the temp goes up a lil bit, rev it at around 2000rpm or so, the coolant level should drop in the radiator, top it up and put the cap on then let it back to idle. leav it for 10 mins or so while running and make sure the temp dont rise too much

thats all i can think off other than doing a head gasket

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I said no to drugs....But they just wouldn't listen!

No matter how good she looks, some other guy is sick and tired of putting up with her crap!

Thanks Noyz, that is a good trick too, I'll remember that one as well. I am in the process now of changing the head gasket.

So, Blue Meanie said that this overheating can happen because the oil now has coolant in it and therefore isn't lubricating the engine properly and therefore the engine heats up quicker. That makes sense because the temp rises pretty fast and eventually the thermostat kicks in, even if it requires me shutting her down for five minutes or so.

So now I am working on getting loose the infamous frozen head bolt between the second and third cylinders (exhaust side). I already broke an extension socket bar and twisted two more. I read in previous posts about using impact drivers, air hammers, and eventually having to drill it out. I sprayed some deep creep on it and will let it sit till the morning. We'll see... I'll update more tomorrow. Thanks again for all your advice and suggestions, it's a big help.

If your radiator core is partially plugged, it can cause overheating in the summer during the day, idling a long time on a warm day. or heavey loads.

Robertcda, thanks, I thought the radiator might be plugged, so I got a new one, but still have the problem.

I just got my head off, it took all day. I got the frozen head bolt off by pounding it with an impact driver, then soaking it overnight in seafoam deep creep. This morning, I put the socket wrench and a cheater bar on it, and it busted loose. It was caked in carbon all on the threads. The other bolts were fine.

Does anyone out there know why the felpro head gasket is missing a hole for coolant to flow through? The old gasket was missing that opening too, but there is a coolant opening on both the block and head there. There was gunk caked on both sides of the old gasket at that opening. It is an opening next to the head bolt hole that is located closest to the timing chain on the coolant manifold side.

could that have been the reason for over heating? not having that flow?

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I said no to drugs....But they just wouldn't listen!

No matter how good she looks, some other guy is sick and tired of putting up with her crap!

I just replaced my head gasket and found the same thing. What I did was cut ever so carefully the slots out and it allowed it to circulate. But before you do this, make sure that there is an opening in the heads for the circulating coolant.

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More LUV than one man could ever need - Spread the LUV!
- 1976 Chevy Longbed - Daily Driver
- 1981 Chevy Shortbed 4X4 - Needs Help!
- 1981 Chevy Luv 4X4 - Newly put together

Yeah, I am on the fence about cutting the gasket. I kinda figure that it worked OK with the old gasket the way it was (gasket blocking the one hole), but I figure there is a reason why there are matching holes in the head and block at that spot.

Meanwhile, I got my head pressure tested and milled after they determined it was out of specs for flatness. It was a little high compared to what I read others paid on previous posts ($40 for pressure test, $50 for milling), but the area around DC here is a bit more pricey anyway. Turns out the gasket blew into the timing chain area from the cooling hole in between it and cylinder #1. So oil was not only getting into the coolant and vice versa, but they were both getting in cylinder 1. Which I am hoping is the main/only reason that that cylinder had a little bit of oil coating the spark plug and compression tester. I was thinking it was likely a a bad ring, but now I am hoping that when I put 'er all back together, that cylinder will work fine. We'll see! I will report the new compression numbers when I get her back together. Before I took her apart, it was 160, 150, 150, 150.

Sounds like you have it pretty much under control. A couple of other things to maybe make things a little easier... get one of those backflushing/ filling kits, it mounts inline on a heater hose, then you just remove a cap to flush things out, or use for the inital fill.
For making holes in gaskets ( I make alot of my smaller ones) I got a cheap set of hollow hole punches from Harbor freight. Just select the correct size for the hole, mark the gasket and hit the back of the punch with a hammer and viola, a clean correctly sized hole. No muss, no fuss.

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Resident lurker

diarmadhim, good idea with the punch! I also got one of those back flushing kits too and installed it before I replaced the radiator. I am replacing some coolant hoses now that I am replacing the head gasket. Where is the best place to install the T from the kit? the top heater hose on the firewall? I had it on the hose coming from the front of the head that wraps under the thermostat to the back of the head/block.

Shouldn't matter too much which one you use...

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Resident lurker

It would not matter for flushing but it should be on a high spot for filling. After you flush and drain, fill it up with the cap off the tee. When coolant comes out the tee, its full. That helps burp all the air out of the system, and you can get see if straight water from flushing comes out first.

On the down side, you can still order the bypass hose that goes from the front of the head to the intake. The hoses across the firewall I have not seen a source for in a while.

That brings up a question for me.

I am about to put in my new eng. (stock).

Any recomendations on where to buy belts, ALL hoses, motor and trans mounts, water pump, and anything else I can't think of right now???

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OK, I'm over it. Where's the beer?

thanks you guys. I'll see about getting a new bypass hose, I put on regular heater hose there but it is kinked coming off the front of the head. I put the T on a heater hose on the firewall high up.

Rondog, I have had good luck from Advance Auto Parts buying all sorts of parts and gaskets. Often they don't have them in stock, but it comes in the next day. I paid about $34 for a water pump last month there. I also bought the head gasket, both manifold gaskets, a radiator cap, new thermostat, and a gas cap (my fourth one!). All were reasonably priced. They did not have the base carbuerator gasket but I got that from a mom and pop parts store in the area. I bought a clutch assembly from Checker Auto Parts out in Tucson (I think around $115) and also both belts. I also got plugs, wires, an ignition coil, distributor cap, and fuel filter from Checker (Alamorgordo NM). I ordered a radiator online ($100 total delivered fed ex to my door) from outlawradiator.com (did not come with radiator cap).


rockauto.com has that bypass hose, but the chain stores may have it too. have fun!