Cooling issue and the blasted HG (1 Viewer)

[Formulaonehd]

Ok so before we all start saying our condolences because yes, my HG blew.....
I wanted to try and understand something in relation to the cooling system on the FZ.

OK so the HG blew in pretty standard fashion, it was the original from 1993 with an engine with very low mileage but none the less, kaboom it went!
Fortunately I never leave home without he Rislone HG fix which just as it claims, will plug those pesky holes. Within minutes the white smoke stopped and the engine ran like nothing ever happened so that I could safely get home in one piece.

Now as the temperatures here have just stared to warm up and not having the time yet to start the HG operation I tried to use my A/C which had just been overhauled except condenser, which is original but great nic from appearance of exterior. Anyway it and was running like a dream after this, that is until now... Well it works but only under a certain temp lets say 30C/86F. Anything over this and the system clicks on an off at the dash panel. The first time I tried to use It was just hot air but each time I have tested it since it strangely got better but never back to how it was after the service.

Ok so my 2 questions are:

1) Would plugging the gasket crack/hole with the HG solution in the coolant, drastically affect the ability to cool the engine or negligible effect? Or can this solution block other parts of the cooling system ie rad or water pump?

2) Should the A/C thermo fan almost instantly switch on when the A/C is switched on?

Thanks all

 

[jpoole]

There are some details here that I'm not familiar with but since you've not gotten an answer I'll chime in:

1) It is possible that the leak fix solution has decreased the performance of your engine's cooling system through clogging.
2) I'm not familiar with exactly what you saying here but can tell you that the AC compressor will disengage when engine temps get high enough. What happens in my experience is that you will be driving along with cold AC that stops blowing cold. The fan in the dash never stops blowing it's just that the compressor disengages so dash air become ambient or warmer.

My guess here is that you may have had an overheating issues before your HG blew. One cause of HG failure can be extreme temperature cycling of an engine. If you think about it, the engine in these is pretty long and the head is aluminum while the block is steel. Those material differences combined with structural differences etc. mean that as temps cycle the head and block are going to move somewhat independently of each other to a certain extent. If you apply extreme heat you may move the cylinder head enough to disturb the HG and open up a leak, esp. near the cylinders at the ends of the engine (#1 or #6). All of that is to say, that if your fan clutch was performing poorly or your radiator is sludged up, etc. and you were repeatedly overheating your engine then that could have caused the HG leak. Add some leak stopping solution to the mix and your overheating problem could still be present and potentially a bit worse for the added sludge.

Beyond that above guess, if you are running hot your AC is going to switch off. Various rigs seem to switch off at different temps but this is a feature built into all of these. If you did AC work recently it may have also lead to an issue and usually I'd just focus on what you've changed recently but your HG failure points to other potential issues.

In my opinion you should:

• find a way to monitor your actual engine temps (if you haven't already) so that you can nail down if your engine is running cool or hot.
  
• test your fan clutch and consider updating fluid or getting a new one.
• plan to replace your HG and desludge/flush your cooling system, radiator, heater cores, etc.

After all of that you should then troubleshoot your AC, if problems remain. It's possible that once your engine runs at proper temps (assuming it doesn't now) that your AC will be fine.

 

[Formulaonehd]

Great response mate appreciate it. This is actually what i am thinking myself and i think it is the gasket that has caused the problem and it has had overheating problems as a result or a quite a while now but never enough to cook the engine. We all now the stock temp guages are pretty rubbish

 

[greentruck]

1) Rislone plugs the leaks, but if the radiator is original, they are tending to plug up now from age unless they've been very lucky with the finest care. You can feel the cooler section or use an infrared temp gun to see them. Rislone isn't supposed to clog a flowing radiator, but often enough an old radiator will not be flowing evenly, so it can limit what extra capacity is left. I'd pencil a new radiator in to other work needing done with the HG.

2. Although people do install the extra electric fans here, the OEM fitment is to just use the standard belt driven fan for both needs. So limited experience. Just guessing what you have, but it's usually set up here as either manually switched or via a sensor. For OEM, I'd bet Mr. T does the sensor. If the sensor is situated in one of the cool, plugged areas of the radiator, it may ironically not be getting warm enough to switch on the fan. However, I suspect you may be able to wire it as manually switched or through a relay as always on as a temp help in your situation. Manual override sounds like a pretty good idea in Australia to me, but you can look up some of the threads here of people who've actually done it before diving into that to assess whether this suits your needs or not.

 

[Formulaonehd]

Thanks @greentruck . The radiaor is new but i do wonder about its cooling abilities. its a 3 core brass with plastic top tank made by Koyo i believe so i'd be surprised if it couldnt keep a standard setup cool enough. I am now convinced the blown HG is responsible and the rislone has plugged a coolant channel causing the engine to heat up too quickly (hence it works fine on cooler days) but until its fixed we may never know

 

[ccslider]

That snake oil, I mean head gasket repair is crap.

It plugs your entire cooling system, works it's way into the heater core, thermostat, radiator, water pump. It usually does more damage than good.

Honestly you know what it needs..

A head gasket and a good flush. If it we're me I would take care of all the while you're in there. Then again that will be a fortune.

Is this your daily?

 

[Formulaonehd]

Yeh thats what i fear has happened. Not my daily no (fortunately) but i had no choice to use it but as you said replace and flush will be the key i think

 

[greentruck]

It can be a long road home in Australia. I wouldn't use the stuff except for limp-home personally, but sometimes that's your only choice.

The folks out West here swear by going with aluminum radiators because there's a noticeable few greater degrees of cooling with them vs brass and if mine ever needs it again, that what it'll get. Brass sounds more sturdy, but since the upper and lower tanks are plastic now, there's less chance it'll ever get soldered in a repair. Keep the brush outta the grille and AL should do just fine. And you need ever degree of temp drop you can get Down Under.

 

[Don Kiddick]

Mate,

While your at it ditch the radiator with the plastic tanks. They don't belong on an off-road vehicle. I know from personal, and expensive experience.

 

[Formulaonehd]

It can be a long road home in Australia. I wouldn't use the stuff except for limp-home personally, but sometimes that's your only choice.

The folks out West here swear by going with aluminum radiators because there's a noticeable few greater degrees of cooling with them vs brass and if mine ever needs it again, that what it'll get. Brass sounds more sturdy, but since the upper and lower tanks are plastic now, there's less chance it'll ever get soldered in a repair. Keep the brush outta the grille and AL should do just fine. And you need ever degree of temp drop you can get Down Under.

excellent point, i do worry about its cooling ability, Is there a way to check whether they are cooling efficiently?

 

[Squash]

If you are OBII compliant a bluetooth sensor works great and in real time.
Plus it offers a few extras.
SCAN CODES
Engine performance
Clear codes.
Using Blue Driver, plus it works on all of our vehicles.

 

[inkpot]

If you are OBII compliant a bluetooth sensor works great and in real time.
Plus it offers a few extras.
SCAN CODES
Engine performance
Clear codes.
Using Blue Driver, plus it works on all of our vehicles.

I dont think the OP has OBD anything ok n Western Australia.

 

[greentruck]

excellent point, i do worry about its cooling ability, Is there a way to check whether they are cooling efficiently?

Sorry, took so long to get back to this. It's been a crazy busy October. With a new radiator, you need to check all the incidentals look to be in place.

You pretty much need to assume that a radiator spec-ed to your truck is designed to adequately cool somewhere on the planet, probably many places if it's a Landcruiser. Now for Western Australia, maybe it is simply mediocre or something, but I rather doubt that. So assume it's good unless you have obvious reason to know otherwise.

About those incidentals...start with the radiator cap, I'd get a new one, just to be sure after all this trauma. Hoses? Guess they look good if they were reused, but take another look. Also look over anything else that carries coolant on the truck. You probably don't have rear heat, but worth verifying. Then it's pretty much all in the engine compartment, including that PITA tube at the left rear of the motor if you have a 1FZ (having a senior moment here.

Where the radiator went in...Was it refoamed? Not sufre there's a kit or you can piece it together OEM, but make sure you do something. That's a biog issue with some who thought that the foam and other ai blocking isn't important. It's vital especially so where things get off the scale in places like WA.

Probably not an issue in WA but too much antifreeze by % in the mix can cause lesser cooling because antifreeze doesn't carry heat as well as real H2O.

Make sure the overflow bottle is properly filled so that the radiator sips fluid and not air when it cools and the level returns to room temp levels,

Yeah, lots of mostly basic stuff. If you find nothing amiss, the high running temps suggest it may be internal to the motor.

 

[Mighty690]

I've got a couple of '93 that I love (and intentionally bought with leaky head gaskets). I also run them in Southern CA and Baja heat. OEM cooling parts and a fresh fan clutch is all I've ever needed, ...well, I have cracked open the fan clutches and changed out the silicone fluid to go a bit thicker. It's an easy mod and may be one of the reasons the rigs (one with a brass radiator, the other with aluminum) have never gotten hot.

 

[greentruck]

I've got a couple of '93 that I love (and intentionally bought with leaky head gaskets). I also run them in Southern CA and Baja heat. OEM cooling parts and a fresh fan clutch is all I've ever needed, ...well, I have cracked open the fan clutches and changed out the silicone fluid to go a bit thicker. It's an easy mod and may be one of the reasons the rigs (one with a brass radiator, the other with aluminum) have never gotten hot.

Yes, good point on the fan clutches, Gooping them to push more air is one of the few pieces of low-hanging fruit to reach for if everything else seems to check OK. I did this after I R&Red my radiator and I think I could still gain some more cooling capacity if I let it run full bore a little longer (to a higher temp really) before it starts coasting. Every hot climate 80 series should have this mod, based on my experience.

 

[Formulaonehd]

Sorry, took so long to get back to this. It's been a crazy busy October. With a new radiator, you need to check all the incidentals look to be in place.

You pretty much need to assume that a radiator spec-ed to your truck is designed to adequately cool somewhere on the planet, probably many places if it's a Landcruiser. Now for Western Australia, maybe it is simply mediocre or something, but I rather doubt that. So assume it's good unless you have obvious reason to know otherwise.

About those incidentals...start with the radiator cap, I'd get a new one, just to be sure after all this trauma. Hoses? Guess they look good if they were reused, but take another look. Also look over anything else that carries coolant on the truck. You probably don't have rear heat, but worth verifying. Then it's pretty much all in the engine compartment, including that PITA tube at the left rear of the motor if you have a 1FZ (having a senior moment here.

Where the radiator went in...Was it refoamed? Not sufre there's a kit or you can piece it together OEM, but make sure you do something. That's a biog issue with some who thought that the foam and other ai blocking isn't important. It's vital especially so where things get off the scale in places like WA.

Probably not an issue in WA but too much antifreeze by % in the mix can cause lesser cooling because antifreeze doesn't carry heat as well as real H2O.

Make sure the overflow bottle is properly filled so that the radiator sips fluid and not air when it cools and the level returns to room temp levels,

Yeah, lots of mostly basic stuff. If you find nothing amiss, the high running temps suggest it may be internal to the motor.

Great response thanks!

Apart from the padding does that foam serve a cooling related purpose ? Never knew .... and no foam was not replaced I think it’s just the rubber grommets in the bracket bolts that separate it from the framework

One thing I noticed is the main bolts that brackets the top half of them rad to to front frame is quite long and touches both edges of the rads thickness (hard to describe and I can’t take a pic right now) I’ve heard electric discharge can be an issue with these bolts

I’m gonna tackle the fan clutch which I don’t think has ever been touched and give the silicone mix trick ago then

 

[Marco Lau]

The 2 bolts that go thru the front core support also go thru a heavy duty rubber gasket/grommets that has a built in rubber cap that covers the nut, so no exposed metal for any sort of electric discharge or current from grounding.

 

[greentruck]

Great response thanks!

Apart from the padding does that foam serve a cooling related purpose ? Never knew .... and no foam was not replaced I think it’s just the rubber grommets in the bracket bolts that separate it from the framework

SNIP
I’m gonna tackle the fan clutch which I don’t think has ever been touched and give the silicone mix trick ago then

Yeah, get something in around the radiator edges. Foam seals and then tends to apply some pressure to keep the seal in place. You want the air going through the radiator as much as possible, not around it. If you can get a look at an 80 with the factory foam intact, that's you best bet for where to apply it, but it's a pretty common-sensical thing once you start looking carefully.

If you're running a stock fan clutch, the goop will work wonders. Does the truck's fan noise roar on start-up? If not, that's the effect you want and it's absence a indicator that adjusting the fan clutch lock-up this way will improve cooling.