MX-3.com

Well i have been looking for a car to take on longer trips as my truck only gets 12-15 MPG, And i found a 1992 Mazda Mx-3 with a 1.6 4 banger with a 5 speed, it has 147K miles on it, he said it just got new CV shafts and new exhoust put on it too.

He was asking $1,300 for it i when there and looked it over, The body isnt the best, it has a crack in the rear bummper and the frunt bummper is missing a chunk out of the frunt bummper. took it for a test drive it shifts good and runs good. i drove it home for $800.

It i have put about 130 some miles on it and it does have some probs, after it gets up to temp when i stop at a stop sign the idle go from 1,000 down to like 100 and keeps doing that tell i start moving again. When i turn it off it smells hot... it doesnt over heat at all just smells hot after i have drove it then turn it off and yesterday i opened it up a bit, (1-4th gear shifting at 4K) well when i stoped it smelled hot and it had a lil bit of some white smoke coming out from over the hood. dont know were it was coming from. Any ideas?


I put some seafoam in the gas and i am going to replace the spark plugs.

trouble6990 wrote:
It i have put about 130 some miles on it and it does have some probs, after it gets up to temp when i stop at a stop sign the idle go from 1,000 down to like 100 and keeps doing that tell i start moving again.

Could be a bad gasket on the TB if it's going up and down. If it just drops and stays down like it wants to die, could be EGR.
Any CELs when this happens?

When i turn it off it smells hot... it doesnt over heat at all just smells hot after i have drove it then turn it off and yesterday i opened it up a bit, (1-4th gear shifting at 4K) well when i stoped it smelled hot and it had a lil bit of some white smoke coming out from over the hood. dont know were it was coming from. Any ideas?

Could be a small leak in the rad. somewhere. It will be enough to give the smell of overheating and give the plume from under the hood.

check for vacuum leaks aswell. they can cause surging idle.

hot smell/smoke is definitely a coolant leak somewhere. i dont know if the rs rad is similar to the gs, but my gs has plastic sides to it. after 18 years of hot and cold the plastic comes very brittle and starts leaking very easily. if you do need a new rad look online or on ebay before you buy something local. i bought my rad for over $300 "at cost" from the local shop, retail was over $450, and ebay has ones for just over $100. if you do need a new rad make sure you get one thats all metal.

Could be a bad gasket on the TB if it's going up and down. If it just drops and stays down like it wants to die, could be EGR.
Any CELs when this happens?

Nope, no CELs and it only does it when it is up to temp and its a surge, the RPM drops from 1000 down tell it almost die's and keeps doing that tell i start moving again.

Could be a small leak in the rad. somewhere. It will be enough to give the smell of overheating and give the plume from under the hood.

I have checked the coolent and it hasnt seemed to have gone down at all.

check for vacuum leaks aswell. they can cause surging idle.

Were are the commen places on this car for vacuum leaks?

hot smell/smoke is definitely a coolant leak somewhere. i dont know if the rs rad is similar to the gs, but my gs has plastic sides to it. after 18 years of hot and cold the plastic comes very brittle and starts leaking very easily. if you do need a new rad look online or on ebay before you buy something local. i bought my rad for over $300 "at cost" from the local shop, retail was over $450, and ebay has ones for just over $100. if you do need a new rad make sure you get one thats all metal.

Is there anything i could put in it to help stop it? or should i just keep my eye out for one for a good price?




Thanks!

if your cheap ive herd putting in 2 bottle caps of pepper can stop small leaks. or for $10 or so theres rad sealer products you can get at any auto store. barsleak is a brand i remember. do you know where the white smoke is coming from? your water pump gasket could be leaking. are you loosing much coolant?

i know for V6's the plastic accordion tube on the intake is known to crack and cause leaks after time. other then that id check all the vacuum hoses for cracks. your idle could also be set too low (shound be around 600-800rpm). if its too low your ecu senses the engine starting to stall so it raises it tries to idle again senses stall then bumps again making the idle jump up and down constantly.

mikeinaus wrote:if your cheap ive herd putting in 2 bottle caps of pepper can stop small leaks. or for $10 or so theres rad sealer products you can get at any auto store. barsleak is a brand i remember. do you know where the white smoke is coming from? your water pump gasket could be leaking. are you loosing much coolant?

i know for V6's the plastic accordion tube on the intake is known to crack and cause leaks after time. other then that id check all the vacuum hoses for cracks. your idle could also be set too low (shound be around 600-800rpm). if its too low your ecu senses the engine starting to stall so it raises it tries to idle again senses stall then bumps again making the idle jump up and down constantly.

I Have no clue were the smoke was coming from, didnt get a chance to look. As far i i can tell the coolent hasnt gone down.



It idles around 1K, untell it warms up then starts to surge.

Here is some photos of the enigne bay.

yeah sounds like your idle is set too low. should warm around 1500rpm then drop to 700ish when at temp (on the gs anyways).

when you car is at running temperature jump ten and grnd in the diagnostic box (on the firewall side behind the battery) with a piece of metal. this will put your car in diagnostic mode. on the top of your throttle body there is a screw, unscrew it until your car idles around 900 then take the car out of diagnostic mode. if you have no vacuum leaks and you did this right your car should be idling around 700 and stable..

trouble6990 wrote:

Nope, no CELs and it only does it when it is up to temp and its a surge, the RPM drops from 1000 down tell it almost die's and keeps doing that tell i start moving again.

I would check the TB gasket. It will result in a leak just like a vac line and is the easiest to try (IMO) instead of tracking down every hose, as well as a rather cheap fix. And hey, if it's not the gasket, then at least you have a new one on and one less thing to replace.

Also a good time to clean the TB since it will be off.

Not to be this guy, but this should have been in the 4cyl section...

A 92 B6E engine should have the idle set at 750. When she's in diagnostic mode you'll want to adjust her to ~850-900rpm. It'll lose 100 or so rpms when you take it out of diagnostic mode.

Looks like the cruise control is disconnected...

Throttle body gaskets are cheap to replace. And mine fell apart when I took the TB off. It's cheap, replace it.
Other places to check for a vacuum leak are: the accordion tube, the PCV valve, the charcoal canister, the brake booster, and the spare hoses running from all the above parts.

The smoke could be from a slight oil leak. Check the valve cover gasket, the head gasket and the camshaft/water pump seals. Could be a coolant leak on the waterpump, or near the thermostat. May even be leftover oil/grease on the new exhaust system.

Is that gray connector above your thermostat disconnected?

The instructions for cleaning the TB are in the 4cyl FAQ section.

Flush your coolant too, change your oil and check for water in the oil/oil in the coolant.

Hey, sorry, i didnt know were i should post it so i whent with this forum.

The cruise control looks like he added it... all i know about it is that it doesnt work... Wish it did tho lol.

Ok, i will get a new TB gasket, also you got me thinking about the valve cover gasket, there does seem to be fresh oil around it, and the spark plug holes were vary oilly.

There seems to be no oil in the coolent and the oil isnt even black yet lol ( Guy just changed it, it looks like)


Witch gray connecter?


Thanks for all the ideas!

Demonic1 wrote:Not to be this guy, but this should have been in the 4cyl section...

A 92 B6E engine should have the idle set at 750. When she's in diagnostic mode you'll want to adjust her to ~850-900rpm. It'll lose 100 or so rpms when you take it out of diagnostic mode.

Looks like the cruise control is disconnected...

Throttle body gaskets are cheap to replace. And mine fell apart when I took the TB off. It's cheap, replace it.
Other places to check for a vacuum leak are: the accordion tube, the PCV valve, the charcoal canister, the brake booster, and the spare hoses running from all the above parts.

The smoke could be from a slight oil leak. Check the valve cover gasket, the head gasket and the camshaft/water pump seals. Could be a coolant leak on the waterpump, or near the thermostat. May even be leftover oil/grease on the new exhaust system.

Is that gray connector above your thermostat disconnected?

The instructions for cleaning the TB are in the 4cyl FAQ section.

Flush your coolant too, change your oil and check for water in the oil/oil in the coolant.

Right here ...


Also I'd double check the vacuum lines for the cruise control. We already know the throttle return cable isn't hooked up... Maybe there are other parts not hooked up.

hey 'am a brand new mx-3 owner as well. i hope she's good to me.

Hey guys, I'm new to this forum and I currently own a 94' MX3 1.6L I-4 with 5 speed manual. The engine just turned 165,000 miles yesterday, and running okay. The MX3 runs great in first 4 years I have driven but it has gone downhill in the past year. The engine temperature goes up when I drive uphill on the highway or sitting idle on the hill without turning on the fan. I just put a new radiator on it, but it still does the same thing and it annoys the heck out of me. The coolant doesn't drop, and it's still green, not as brown I seen before the replacement of the radiator.
Hey, I'm from Connecticut.. Any ideas for MX3 meets in the tri-state area?

Well i have the TB and valve cover gaskets ordered we will see if that fixes it.

I took 2 videos of the way it idles at op temp, one was when i was siting at a stop sign, clutch in foot on brake and the other one was siting in a parking lot in N, with my foot off the brake.

And that is were it idles when it is first started (cold)






http://img828.imageshack.us/img828/8679/0805101444.mp4

http://img836.imageshack.us/img836/5503/0805101448.mp4

Also I'd double check the vacuum lines for the cruise control. We already know the throttle return cable isn't hooked up

The TRC isnt hooked up?

Were would the VL be for the cruise be?


I am new to this engine/car.

If it was a chevy truck with a V8 i would know a lot more lol.