Craigslist score.

[AZ200cc]

Originally Posted by TurboT

Wow.. that was some write up on 'stretch' bolts. We have an engineer amongst us! I always knew of them as 'torque to yield' myself.

I have 14 years in an engine shop. I've pressure tested and surfaced so many of those Mazda heads I lost count. If the problem was a cracked head, or head gasket problem, the engine would be smoking like crazy due to the antifreeze or water burning off in the cylinders, or running like sh-- since the compression would be seeping out of side where the gasket was split.

If none of those are apparent I would expect it's a cooling system problem like you're investigating. This is of course not my specialty as I was always working on the internal components.

LOL no we have a guy who can google for some person who has already typed it up and save myself an afternoon

You'll get it Kato, You're a sharp knife

[TurboT]

Haha... It was an interesting read for sure!

Reading all that about Mazda heads brought me back to my former life! They are bad for gasket etching into the block as well. Aluminum head and Iron block syndrome. You pull the gasket off and it looks like it's still there!

Many people just replace the gasket and don't surface anything and the etching is so bad in the block it just puffs again.. however I don't think that is the issue here since it doesn't sound like a gasket issue.

However with enough overheating the head will warp eventually and blow the gasket!

[Weldangrind]

Originally Posted by katoranger

Well, I don't its the head gasket. No signs of coolant in the oil and the oil level is correct. My Dad said it was fine until he got into some traffic and then it started getting hot.

I think the fan clutch may not be working. I pulled the thermostat housing off and the thermostat was missing. The pump seems to be pumping, but is suspect.

Pulled the radiator out and it looks good. Looks to be pretty new.

It wasn't smoking or missing on any cylinders either.

Allen

I believe part of the problem to be the missing thermostat (stay with me). Somebody likely removed the thermostat in response to overheating issues, perhaps due to a poor clutch fan as you say.

Old hot rodders (my Dad included) would often remove the thermostat to crutch the system, not realizing that often creates a problem. The thermostat is not only a valve, but also a restrictor. The key is in the size of the coolant passage that is exposed when the thermostat is fully open. Removing the thermostat completely causes the coolant to flow too quickly through the rad and return to the engine without sufficient contact time that any heat exchanger needs. If you insist on removing the thermostat, gut an old one to approximate a fully open thermostat.

On the matter of the head, I agree that the head and block need to be properly prepped and squared before a new gasket can be installed.

I'm glad to hear that you're not finding milkshake in the oil. Are you finding oil droplets in the coolant?

[katoranger]

No oil in the coolant either. I think we have a combination of no thermostat and a failed fan clutch. Not real sure how to test the fan clutch. I believe it works on heat doesnt it?


The radiator looks good and clean. My Dad said it was fine until he had to stop and then it would get hot.


Also the previous owner said that they machined the head when they did the gasket. I don't know if they did the block.

Allen

[suprf1y]

My rad, and fan looked fine too, but one spring day, as the weather warmed, it just started running hot. I went through the process of elimination, and ended up changing the rad.

[knothead]

Originally Posted by katoranger

No oil in the coolant either. I think we have a combination of no thermostat and a failed fan clutch. Not real sure how to test the fan clutch. I believe it works on heat doesnt it?


The radiator looks good and clean. My Dad said it was fine until he had to stop and then it would get hot.


Also the previous owner said that they machined the head when they did the gasket. I don't know if they did the block.

Allen

With the engine off (yeah, I know that you know, but....) try to turn the fan. It should turn but be really stiff. If you can turn it easily, it's bad. At least that's how Toyotas and Jeeps are..

You can get a solid (non-clutch) flex fan pretty cheap. As long as you don't try any deep water crossings they work fine.

[katoranger]

Yep. I can turn it pretty easy. It has some resistance, but not much. I tried heating alittle with a propane torch and it didn't seem to engage either. I don't know if that was a good test or not.


As for the radiator. I am going to price a new one. It won't hurt to make sure its good. I can be cheap in other areas.

Since I don't need it for a daily driver, I can take my time to get parts.

Here is some pics. I added some redneck chrome over the rust holes in the rain gutters. This is a FL coast truck.


http://picasaweb.google.com/katoranger/Mazda#

[AZ200cc]

Heck, It not in badshape, Interior seems pretty good. Could be a good getaround truck once You figure it out.

[Weldangrind]

Keep shopping for a factory style clutch fan. Marlan Davis of Hot Rod magazine says that they're the most efficient at cooling, and they don't rob as much horsepower when they're not engaged.

Failing that, I'd be tempted to switch to a junkyard electric fan and shroud. The Ford Taurus fans are popular with hot rodders because of the size and cfm rating. You could wire it through a simple factory temperature switch and then have a toggle that would allow you to bypass the temperature switch if it fails. Did I say if?

[katoranger]

I am going to just replace with an OEM style clutch.

The truck is pretty straight. Has 4 new tires and the interior is almost perfect.

Also is has AC.

This will be my winter commuter/scrap hauling/craigslist/garage sale vehicle.

I will be posting some or yesterday's garage sale finds in the for sale section. Need to make some money to buy the parts for the truck. Also pay for the tag and insurance.

Allen

[iMoose]

Good score! ANY running vehicle for $150 is a deal.

I found a '97 Nissan for $800 (book is $3k!)

Had an almost identical overheating problem. Whoever last changed the thermostat, which was recently, placed it backwards in the housing.

So after $7 later from AutoZone, great running Nissan. It's a 2wd, but it's perfect for hauling my junk to and fro. It's even an extra-cab so I can take my crazy dogs with me. lol

And the best thing about 2wd 4-cyl Japanese trucks.....gas mileage! I swear this thinggets 30mpg! Ok, maybe not 30..... but dang close!

Craig's is a good source for deals, but ya really have to look hard nowadays.

There's so many people that have totally unrealistic ideas on pricing. Especially in this economy.

[katoranger]

I am hoping to get 25mpg commuting. My jeep only gets 14-15 usually.

I found today that I can get the carseats installed in the back. I can take all 3 girls with me for home depot runs and such.

I think I am going to try to just replace the thermostat and the fan clutch and see what happens. Just drive around my neighborhood an see if it gets hot again. If so we will go from there.

Allen

[iMoose]

Mind a suggestion?

I have a metal garden hose "nozzle", JB Welded into a trimmed hockey puck. That then simply connects to city pressure via garden hose.

Why? To make a sort of seal to "flush" the cooling system.

Because as I learned with my old CJ's and Toy 4x4's, it's a VERY good idea to try and flush the engine when changing the water pump. Whatever crud fouled the pump and/or T-stat, could be floating around and clogging the cooling passages in the block too. It takes a while, but there's a weird sort of self-satisfaction ya get when clear water starts flowing out from the bottom inlet. lol Maybe it's just me.

I worked as an auto mechanic for several years(18-24), and one thing I learned from my old Polish master tech was.....

"A clean engine, inside and out, will last 3x longer than an engine merely patched with fresh parts."

Don't even get me started on cleaning oil passages and valves.

Some guys have porn, I have my "projects". lol

[katoranger]

I have thought about trying to flush it out.

Where to place it to flush it out?

Allen

[iMoose]

Take off the bottom radiator hose, and when you have the water pump OFF you'll see the "hole" or inlet where to put the "plug" you've made.

Or you could really just stick a garden hose right into some inlets. Some are small enough to not need a homemade "plug", like I made.

I made that plug because some cars are different, and I liked the fact I could make a seal.

The key is patience....and a big pan to catch the water! You will have to be able to turn the water on though WHILE holding it in place. Otherwise you'll wind up with one of those weird yard toys for kids, called a Wet Willey.

Ya don't want coolant dribbling into your yard. Especially if ya have dogs. They absolutely LURVE the taste of coolant, but it's highly poisonous to them.

A couple laps could kill a dog. So please be careful!

*note* I used a hockey puck because I could easily drill the center hole for the nozzle, then trim down with a combination of saw/dykes/dremel. Ultimately making a kind of big "cork" like for a wine bottle. Takes a while, but dramatically improves the "effectiveness" of the process.