Strange and puzzling.......

[SuzukiGhostRider]

Ok, so the other day I got to bleed my coolant system two days in a row. I had discovered (after two months of having this car leak free from being the oil and coolant leaking cistern it was when I bought it) a small coolant leak. I tracked it to the other TB line I HADN'T replaced (replaced the first when I found a crack in it).

So , that pissed me off enough, I said to hell with the damn TB Coolant lines and pulled them out and installed brass plugs. Nuff said, done and good riddance.

Next day (when replacing the lines with plugs, I noticed my upper rad hose was bulging slightly at the t-stat housing and mentioned to the woman "that's gonna need to be replaced pretty quick" and jinxed myself) I blew my upper radiator hose at the end of my driveway coming home. Talk about good luck! Any place to break down , it's AT HOME where my tools are!

So...... I replaced the upper hose the next morning and bled the coolant system AGAIN......

Now, since I replaced the lines with plugs I've had piss poor heat in the car. This is a car that less than a week ago , on a cold mountain night like tonight would have you BEGGING me to turn down the heat, and that's when it was on 2 ,not 4. Now on 4 I've got VERY lukewarm, almost cold air. Keeping in mind , the "cold heat" has been going on since the night I plugged off the TB lines even before the upper rad hose blew.

So tonight, I got under the car while running, and grabbed my heater core lines. The one coming off of the t-stat housing (feed line) is nice and hot. The one running from the heater core to the water pump metal line (return line) is cold.

So , I presume I've got a blockage, but wanted other opinions on it and solution suggestions. I can't understand what could be big enough to be blocking the heater core lines as they're fairly sizable......

I had also noticed the car runs a GOOD 30* cooler on average than it ever did before and found it shocking since all I had removed were the small TB lines. Now I know why so cool. The coolant is being stalled before it ever gets to the heater core apparently and it's the equivalent of having it bypassed.

I was thinking of a flush to clear the blockage.

Suggestions?

[Barry]

Take the hoses off the core and blow it out with a garden hose.

[DTMAce]

Agreed, may have to blow out each line/passage, and probably from both ends, as you don't know which end of a hose/core/block passage has the blockage.. Problem is, if something could be blocking a heater line, it could also move and block a passage in the head, and you don't want that...

[SuzukiGhostRider]

Actually I'm pretty sure I DO know which end is blocked as I have no heat, and the return line from the core is cool why the entrance line is hot. I'm just puzzled. I mean, that's a HELLUVA line to block completely outta the blue. It's a 5/8" inlet and a 3/4" outlet..... It would take a sizeable object to block that inlet line and all of a sudden like that... Makes no damn sense.

I've been under and all over the dash and under the hood checking vacuum connections, and making sure the fresh air door opens and closes as it should,etc. I wondered about the heat blend door, but that makes no sense as the outlet line from the heater core should be hot whether that door is working or not!

I just can't figure wth would have gotten loose in the system to block such a large line.......

I've never had cooling issues with the engine and I've always had GREAT heat. And I know for a FACT I didn't ,and really couldn't have, lose anything into the system by plugging off the two TB lines...

I guess tomorrow will tell. Here we go 3rd damn time this week losing coolant and burping the friggin' system.

This car is starting to piss me off.....

[SuzukiGhostRider]

So,I was wrong about the inlet hose getting warm. There was JUST enough exhaust manifold peeking out below the hose to make it SEEM warm to the touch, but if I grabbed it a few inches further down it was cool as is the outlet hose.

So , anyhow, I think I've solved my problem. I put 1/2" deep brass plugs in the TB coolant line holes. The one on the water outlet sank almost flush with the end of the threads. Well, it seems the TB coolant line and heater core inlet line share a common feed line. First the TB line and then further down the hole, the heater core line. So, I got to looking at the connector between water outlet and TB line I removed to install the plug.

Guess what?

Only a 1/4" of shiny used threads vs. the 1/2" of plug now inserted in the hole.

Conclusion? I accidentally all but completely blocked off flow to the heater core inlet hose through the shared duct for the TB line and heater core inlet line.

We'll see tomorrow if I was right or not.

Damn the parts stores for not being open 24/7!

[3X00-Modified]

Are there any alternatives to the heater core supply line that will eliminate the plugs you had to use?

I know for 3100 guys if you get I think, 94 and older heater core lines they don't have the TB heater outlets... it was only 95+ or something like that. Also as I have now we can switch to the older 91 style 3.1L supply line that routes the other way and use a Minivan Tree at the water pump.

I find it odd that older quads had TB heaters where some of the 3100's just didn't even come with them.

[heavywoody]

My car never had TB heater lines, on the heater core or on the TB.

[3X00-Modified]

Must be a 96 thing then, because I do remember now my 95 also not having them. It was the 3400 TB with the inlets that I was originally confused on what they were for when I did my 3400 top end a long time ago.

[woody90gtz]

My 95 didnt either.

[Cliff8928]

Damn the parts stores for not being open 24/7!

You obviously don't live in the right area then...

Must be a 96 thing then, because I do remember now my 95 also not having them. It was the 3400 TB with the inlets that I was originally confused on what they were for when I did my 3400 top end a long time ago.

My 3400 did have these lines when I got it, I remember pulling that coolant line from a '94 to have one without the TB heater.

[speedy]

i know whats wrong... and i didnt even have to read the post to come up with this conclusion... just the "strange and puzzling" topic was enough for me to say....

TYPICAL QUAD 4!

[Barry]

My 95 3100 had tb lines the 94 3100 did not

[SuzukiGhostRider]

Every Quad HO has TB coolant lines. Or HAD them and now they're bypassed. At least that I'm aware of. Remember it was and is , a much higher strung motor than the 3100.

Well, still no heat. Inlet hose is getting warm now, so I guess tomorrow is remove the lines and flush the heater core day.

[speedy]

wrong sgr. my 94 didnt, im not sure if the 91 does or not, i know for a fact that the 1990's had them, maybe your 92 does?? maybe it was an option?? who knows...

[SuzukiGhostRider]

No it wasn't an option. If your '94 didn't have them someone either bypassed the lines or installed a different water outlet housing. I KNOW '93,'92, '91, and '90 had them FOR SURE because I have/had all of those year Quads.