Diaries of the Noob Mechanic: Fuzzydunlop's '85 MR2

[Zargon]

nice!!!

 

[5150MyU]

About your oil presure switch, it is a single wire variable resistor (rheostat) sensor.
JCH13 was correct.
You can hook up a mechanical gauge to that port to see if it agrees with your dash gauge and as long as it agrees and the sensor isn't leaking all is good.
Sorry I didn't look into it more.

 

[FuzzyDunlop]

About your oil presure switch, it is a single wire variable resistor (rheostat) sensor.
JCH13 was correct.
You can hook up a mechanical gauge to that port to see if it agrees with your dash gauge and as long as it agrees and the sensor isn't leaking all is good.
Sorry I didn't look into it more.

Umm, mechanical guage? Define. Im still learning these things! lol.


Out with the old

In with the new

Im still waiting on my SS brake lines (holy moly, i ordered these back on April 29!). Tracking says its in transit to my town - hopefully tomorrow - but really there is no rush - I can install them anytime. Its just that I think it would just be easier to install them without all the suspension parts in the way.

 

[Aikouka]

Oooh shiny! Shiny good!

 

[Pulsar]

Your oil pressure gauge monitors oil pressure, not level - you'd need to be pretty low on oil for the pressure to drop. It should fluctuate a bit depending on RPM..i.e. higher oil pressure when you're running the RPM's up higher. Does it do that, or is it fixed in one position?


Mk1 MR2s have an actual pressure gauge - I wouldn't use it in place of a "real" gauge for a high performance build, but if he's just going to run a mostly stock engine I'd just use the stock one.

Most oil pressure gages now are just on-off switches set to trip at a specific pressure. It's cheaper for the manufacturer and it also turns out that consumers like it better when their oil gage doesn't move at all.

 

[JCH13]

Most oil pressure gages now are just on-off switches set to trip at a specific pressure. It's cheaper for the manufacturer and it also turns out that consumers like it better when their oil gage doesn't move at all.

Where are you getting your facts?

I've never been in a car where there was an oil gauge that wasn't a real pressure gauge. The pressure switches you are referring to merely turn on the idiot light if there is low or no oil pressure. At least in my experience.

 

[FuzzyDunlop]

Another question for you guys.
When I was installing all the suspension the CV joint fell out and a bunch of grease went splattering everywhere. I also lost a bunch more when I reattached it to the tranny.
Question is... how do I fill that up with grease again? and does it need to be that full?

 

[JCH13]

I've just packed them by hand then slipped the boot over. Fresh grease won't drip out. And yes, it probably needs to be very full.

 

[FuzzyDunlop]

I've just packed them by hand then slipped the boot over. Fresh grease won't drip out. And yes, it probably needs to be very full.

hmmm. ya, I guess Ill have to take it apart again and repack it. What kind of grease does one use for that? Is there a bearing specific grease I should use?

 

[JCH13]

If the manual calls for something specific, go with that. For FSAE car's I've just used a synthetic CV joint grease. Can't go wrong with Redline usually.

 

[NutBucket]

Do you mean the boot fell off or the axle came out of the transmission?

 

[jlee]

Most oil pressure gages now are just on-off switches set to trip at a specific pressure. It's cheaper for the manufacturer and it also turns out that consumers like it better when their oil gage doesn't move at all.

Having owned a 1986 MR2, I know from experience that the gauge is not simply switched on/off. My Tundra also had a real gauge.

 

[5150MyU]

Mechanical (live) gauge, this guy shows what he is doing off the car so you understand what he is doing on the car.
http://www.youtube.com/watch?v=y221Lu8DD5M

BTW the specs for your vehicle at operating temp. are:
3,000rpm's 36-71psi.
At idle greater than 4.3psi.
That 4.3 sounds kinda funk, but that is what it says.

 

[FuzzyDunlop]

Short update here.

Rear suspension is completely done on both sides.

While I had the wheel well empty on the passenger side I decided to drop the oil pan and re-gasket it. I also painted it, which was probably unnecessary but makes me happy when I look at it now. Took me about an hour just to get it clean enough to accept paint. See above pic for results.

Also found Top Dead Center. (I marked the crank with some silver paint to make it easier to see). So once I get a new oil seal for my distributor (hopefully tomorrow) I should be ready to throw some fresh oil in and get it started again.

Sure glad I bought that in/lb torque wrench. Once I felt how lightly I had to torque down the oil pan bolts I became immediately aware of how important it was to have one. - I for sure would have broken a bolt with out it. The wrench is also very easy to use, and very clear about when you’ve reach the torque limit. A+ review so far.

Lastly, I dropped the front bumper and saw this on the radiator

Needs replacing?

 

[Eli]

LOL

Wow. I'd say "needs replacing" is an understatement.

 

[FuzzyDunlop]

LOL

Wow. I'd say "needs replacing" is an understatement.

nuts. hmmm. ill tack that onto my "to do" list.
Ive been putting off flushing the coolant system in this car because it is a BIG job due to the rear engine set up. I also need to do it outside of my garage due to the amount of water ill be running through the system.
But, i guess ill start searching for a replacement radiator for when I do get around to doing that.
sucks.

 

[Aikouka]

Would it actually be bad with it only missing maybe 15% of the fins? It certainly can't be worse than something like a bad radiator fan... you usually find that one out real quick when you're stopped .

 

[jlee]

I don't know if it works with the Mk1 as well (I assume it does), but rather than going through the rather complicated coolant bleeding procedure, I jack the back of the car up as high as I can get it, support the car on jackstands (front wheels chocked, of course), then fill the coolant from the filler cap. Turn the heater on full hot and start the car - the fill point now should be the highest point in the cooling system. Keep adding coolant as bubbles come out - once coolant starts coming out without bubbles (as the coolant expands due to heat), cap the filler and shut the engine off. Check/fill the reservoir as needed and you should be good to go.

It's way easier than using the multiple coolant bleeder locations.

 

[FuzzyDunlop]

I don't know if it works with the Mk1 as well (I assume it does), but rather than going through the rather complicated coolant bleeding procedure, I jack the back of the car up as high as I can get it, support the car on jackstands (front wheels chocked, of course), then fill the coolant from the filler cap. Turn the heater on full hot and start the car - the fill point now should be the highest point in the cooling system. Keep adding coolant as bubbles come out - once coolant starts coming out without bubbles (as the coolant expands due to heat), cap the filler and shut the engine off. Check/fill the reservoir as needed and you should be good to go.

It's way easier than using the multiple coolant bleeder locations.

haha, thats about 8 paragraphs shorter than the *official* procedure I saw at MR2OC

- where did you drain from?
- why should you turn the heater on?
- did you flush the system with water and then add coolant afterwards like the dude at http://www.padandwheels.com/mr2/waterpump/coolant.html had done?
- have you ever done a radiator flush? - I wonder if its necessary.

 

[Zargon]

having done a coolant change on a car that hadnt had one in 115K miles, its usually kinda necessary, the bottom 3rd or so of my wifes old cars rad tanks was full of jello like sludge

 

[JCH13]

I would (actually, I did) replace the radiator, major cooling hoses, and thermostat. Especially if you plan on driving the car hard.

 

[jlee]

haha, thats about 8 paragraphs shorter than the *official* procedure I saw at MR2OC

- where did you drain from?
- why should you turn the heater on?
- did you flush the system with water and then add coolant afterwards like the dude at http://www.padandwheels.com/mr2/waterpump/coolant.html had done?
- have you ever done a radiator flush? - I wonder if its necessary.

1) Drain from the petcock on the bottom of the radiator.
2) It opens the heater core for coolant - if you don't, you won't get the air out of the heater core.
3) No, but it might not be a bad idea.
4) No, but I should (might do that on Thursday, assuming I get the car running by then). My coolant is brownish and nasty.

 

[JCH13]

2) It opens the heater core for coolant - if you don't, you won't get the air out of the heater core.

The heater switch actually controls a water valve to let fluid through heater core? It doesn't just control air in the HVAC plumbing?

 

[NutBucket]

That's correct.

 

[Zargon]

yup