Ok, trying to get my 1990 Camry up to par and the next issue on my list is that the heater isn't working (in the Canadian climate, this is not a good thing!)
I installed a new thermostat: not the problem, there was still no heat.
Today I flushed the heater core with water from the garden hose, three times both ways. I'm hoping that did something. I'll have to wait to check it because the water by-pass pipe rusted through and was leaking coolant so I had to take it out and am trying to find a replacement.
Should I just go ahead and replace the heater core while I have all the hoses off? Or do you think I should wait and see if the flush had any effect first? Is there any other option I've missed with regard to this lack of heat problem?

I'd appreciate any suggestions!

-Mike

 

If the temp gauge is indicating the engine is operating normally the T-stat is working OK.

The two by-pass pipes flow coolant to and from the heater.

The tube connecting to the coolant outlet port going to the top of the radiator being the heater return hose.

Make sure the heater valve controlling coolant flow to the heater core is not stuck closed.

Before replacing the heater core disconnect two hoses going to the core (coolant in and out). Suggest disconnecting the hoses at a place other then the firewall tubes as these tend to be made of soft brass/copper and bend easy when attempting to remove a hose which is often stuck to the pipe.

Once the hoses are disconnected run a garden hose into coolant return hose to back flush the heater core. If possible, run the water coming out if the other hose into a bucket to check for debris coming out.

If running the water through a hose still having the coolant valve connected to the heater temp control, make sure the valve is full open.

It might be possible to use heater hose in place of the rusted out pipe. Perhaps a short section still exists that the heater hose can be slipped over then clamped. Keep the hose away from the exhaust manifold.

 

Well, I flushed the core and had a plastic container to collect what came out, which wasn't much at all (I watched a demonstration of a core flush on youtube and his core was really gunked up.....mine didn't seem very clogged at all).
The temp. gauge indicates normal engine operation so I can safely assume the thermostat is OK.
If I've done a flush and water moves through the core unimpeded, that means the heater valve is not stuck closed, right? Seems logical.
And the water by-pass pipe has a tiny branch that shoots off the end at a ninety degree angle (not sure where it goes or what it does). That's the part that rusted through. I'm going to see if the one on my parts car will fit. If that doesn't pan out, there's still about 3/8" of a stem left on the pipe that I'll try to clamp the hose onto.
I'm headed out today to take another crack at it.
My plan is to get that water by-pass pipe re-installed and then to reconnect all the hoses to see if the flush accomplished anything.
If there's no heat after that, replace the heater core???

Cheers,

-Mike

 

My parts car is a V6 and has a totally different layout than my 4 cylinder....I couldn't spot anything resembling the water by-pass pipe on the V6. None of the parts places I saw carry it and the Toyota dealer wanted $200.00 + for the part!
I called a local auto wrecker and the guy said he'd call me back. I didn't receive a call so I'll call back in the morning. If that wrecker doesn't have it, I'll go through the phone book and hit up every auto wrecker in town to see if they've got a 1990 Camry in the yard I can salvage for the piece.
If no one has one, I'll give my friend G. a call....he's a metal worker and can probably weld something together for me that'll do fine.

 

I guess your friend G got a good hand on mechanics... he can do magic on that.

 

The V6 may have the tube running down the center of the engine between cylinder banks. It starts at the water pump and runs to the drivers side of the engine.

The other pipe end fitting may be tied in some place on the water outlet pipe from the head.

As with the 4 cylinder these pipe and the other fitting are what flows the water to the core.

Follow the two hoses coming off the firewall, they will go to the cooling system.

If the heater flows water OK it should work OK.

Fix the bypass system and determine what happens.

The V6 of this year was only used for 1-2 years. This could be a reason your having such a hard time finding the pipe. Your friend could weld or braze a pipe extension on. Or get another section of pipe the join the two with heater hose.

 

I went out to a local wrecking yard and found what I was looking for! I actually got two pipes. On the first pipe, the metal near the 'O'-ring had corroded away and was likely too far-gone to seal.....but the other end of the pipe was in good shape. On the second pipe, the 'O'-ring end was in great shape but the little pipe at the other end had some serious-looking corrosion on it. The guy said I could combine the pipes into one, so I paid my $30.00 and was happily on my way.
When I got home, I put the second pipe in a vise and began taking the rust off with a drill and a wire-brush bit. Being very cautious around the little pipe at the end, I scoured off the rust. Surprisingly, the corrosion hadn't eaten through the little pipe. It still had some measure of strength in it.
I put two coats of that steel weld gunk onto the little stem to give it even more strength. Today, I'm going to spray a coat or two of rust paint onto the pipe and re-instal it.
And I'll see if I have any heat! Here's hoping....

 

Great job! Post back on the results. Hopefully you will have heat once more.

 

Success, I have heat! Ahhh, did that hot air ever feel good blasting out of those vents!

Thanks for the help,

-Mike

 

Glad to help.