Help with Laser and rough idle +VIDEO

[Dhan]

Hey all, I picked up a FWD turbo Laser, no mods, with 106K. It has a couple issues that I was hoping to get some help with. It seems to run all right, but the idle is a little funky and I don't think the oil and temp. gauges are working properly.

The oil gauge needle will swing in between the area I marked in red in the picture below.
The temp. gauge takes a long time to get to normal operating temp. and never quite reads what I think is normal. I'm used to my Inline-4 Mazda being at operating temp. in just a few minutes of driving. In the picture below the area marked in red is where the temp. gauge needle hovers. It never gets quite to the center.

Bare with me, the videos are at night, so there's nothing to see. The first video is just of the engine idling, the second video starts at the exhaust pipe, then I move to the passenger side, then to the driver's side of the engine, hood shut.

Does anyone know where I should begin when I get another chance to work on it in daylight?

 

[Absit]

Idle:
Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)
Oil Pressure:
The sender's crap, and probably wrong - buy a real gauge.
Temp:
Your thermostat is bad.

 

[Dhan]

Idle:
Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)
Oil Pressure:
The sender's crap, and probably wrong - buy a real gauge.
Temp:
Your thermostat is bad.

Thanks for the info Absit. I figured the oil and temp were going to be simple fixes, I just wanted a more informed opinion.

I've seen that article about idle surge before and it's what I thought at first too, but the article describes idle surge as oscillating RPMs between 1200 and 1500. My car's idle has a constant loud and low whir. The RPMs are steady. It almost sounds like a diesel kind of sound, which I can only guess is engine knock. The gas in the tank is supposedly premium, so I'm stumped.

Of the four Autolite 63 platinum plugs I pulled: two are gray, one is a little whiter than the others, and the last one is a little blacker than the others. I'm going to pick up the appropriate NGK plugs instead and replace the old wires first chance I get from here...STM: NGK PREMIUM WIRE SET | 90-99 DSM
Maybe that'll make a difference.

 

[Absit]

Yes, put proper plugs in and see what happens. I can't really tell from your videos what's wrong with your idle.

 

[Dhan]

Well, I finally got a sunny day off and fixed my thermostat and oil sender. Fired up the car with expectations to go for an afternoon cruise. these plans were soon dashed when I heard a loud rattle that wasn't there before.

Sounds like it's coming from the t-belt, so I remove the shroud and now the belt is all loose and floppy. Not sure how this happened. It hasn't done anything but sit in the parking lot for the last week.

My question is, should I tear it all down and do the water pump, BS belt, and t-belt, or can I adjust the tension w/o taking it all apart?


YouTube - DSM t-belt tension

 

[dsmspick]

They have an auto tensioner, it might have gone out. So either way your going to have to take it apart. Might as well do it right and replace everything.

 

[DSM1G90]

If you have a 195* T-stat in that thing, the temp needle should be just before the half mark and normal temp.
Oil pressure needle will swing when you change your RPM's from idle to road speed. Maybe the MAZDA/FORD doesn't do these things, but Mitsu likes to be more accurate.



106K miles on it ... dang betcha you'd better do a belt/wp/roller/tensioner kit. Definitely looks like the tensioner kiss it to heaven!

What I did with my Laser when i got it - brought it home took it on the back patio and did the whole smeer - T-belt was shredding on the upper surface, both rollers had bad bearings, weak tensioner and tired wp.

24k miles later, still runs like a top and it still scares me to drive it with the power that can still come out of it .. in stock form. - DSM