Overheating issue - I am stumped!

[wilkin250r]

I highly doubt the heater hose routing is causing an overheating problem. Yes, the heater core will dissipate heat, and it will technically help cool the engine, but not a significant amount. IF the temp gauge is accurate and it's climbing to 250 degrees, the best heater core performance wouldn't bring that below 240.

By all means, fix the heater hose routing, but I wouldn't expect it to cure your problem. There's still something going on, whether it's a faulty temp gauge, or bad thermostat, or water flow problem. I doubt the heater core flow and routing will affect anything more than a few degrees.

[rich weyand]

It's not the heater core dissipating heat. The issue is that there needs to be circulation within the engine before the thermostat opens, to eliminate hot spots and to ensure the thermostat sees the heat it needs to open. So there has to be circulation. To that end, the stock heads have a bypass, that routes water around in the engine when the thermostat is closed. The heater core can also serve as such a bypass. The issue here is the the OP does not have correct coolant circulation within the engine.

[WyattTX]

This may sound ridiculous, but do you have a fan shroud? If not, put one on, that would make things a little cooler.

[Katrina/10]

I don't think it makes any difference if the heater core is connected to the front, back, or not at all, as I have run many engines with no heater connection and never had this issue. It has to be something in the engine itself.

[rich weyand]

Summit confirms that those heads have the internal bypass. I have not been able to confirm whether the Fel-Pro 501SD gaskets have the bypass holes, but I would be surprised if they didn't.

Another thought occurs. Is your radiator stock cross-flow, or is it a serpentine radiator (rare, but thought I would ask)?

[Mattchu60]

Thanks for checking that for me Rich. I was hoping to have a bypass to the water pump put together by now but I have had no luck getting fittings for the hoses, all the parts stores have are steel fittings and I would like to have brass, the local Menards plumbing section didn't have anything either. Going to have to go online to get what I need, so it'll be a week or so before I can report back again.

The 180 stat is helping some, gets the T-stat open faster so I am not getting to 250ish degrees now, saw 230 today then it dropped.

[Dead Parrot]

For testing, steel should be fine. If it fixes the problem, then order the parts you want long term. Be sure you leave a bit extra on the hoses if you go this route.

It will suck if you wait and worry a couple of weeks while the brass parts show up only to find out they didn't solve the problem. And you will know exactly what parts to order.

[Katrina/10]

Originally Posted by rich weyand

Summit confirms that those heads have the internal bypass. I have not been able to confirm whether the Fel-Pro 501SD gaskets have the bypass holes, but I would be surprised if they didn't.

Another thought occurs. Is your radiator stock cross-flow, or is it a serpentine radiator (rare, but thought I would ask)?

Can you describe any more about these bypasses? Where are they, how do they work?

[Mattchu60]

Been on vacation for a week, got back home yesterday and had a few packages in the mail with my brass fittings. I installed them today and made a bypass from the intake manifold to the water pump, I also put a proper heater hose connector in and ran new hoses for the heater core.

After 2 drives I believe the problem is solved, the temp does not get over 210 on the gauge now (running 195 stat). It was obviously not circulating coolant evenly around the heads in the old setup before the T-stat opened which was creating a hot spot.

Thanks for all your help, I am glad this is solved because it made me very nervous to see that gauge climbing all the time on startup!

I'll try to get a picture up of the engine bay now, looks a little cleaner.

[rich weyand]

There ya go! Congrats.

[cadillac_al]

So moving the heater hose from the radiator fitting to the water pump solved this issue? I may try this on my car in the near future just for the fun of it, even though the temp spike never alarmed me before.

[Mattchu60]

The heater hose still returns to the radiator. I added an additional short hose that runs from my intake to the water pump. I'll try to get a pic up in the next day to show what I mean.

[Front Range]

Way to hang with it, glad you solved it.

[Mattchu60]

Here is a picture of the engine bay now. You can see the short red hose between the intake and water pump in this, I also cleaned up the heater hose from the intake and the coolant sensor with some new fittings.