Plain Jane OEM nothing to see here rebuild

[JL1RX7]

Or it running too rich, too much premix/oil. Those would be the big ones. If I recall correctly their used to be a sticky on the evil forum showing all the different pictures of plugs and what they mean. Always something useful to have to do a quick visual check of what you got.

[RETed]

Originally Posted by JustJeff

One thing I forgot to mention. I had always assumed the fouling plugs is due to coolant seal leak. Thoughts on this?

Yes, coolant on the spark plug tips will kill them in short order.

You can do a quick & dirty test with a DMM...
Measure resistance from the spark plug wire end to the center electrode (in combustion chamber).
Check this same measurement on one of the brand new spark plugs.
The used spark plug should be *less* in resistance due to the center electrode wear down slightly.
If the spark plug is "fouled", the resistance is going to be significantly higher.
I forget what what these NGK BUR/EQ's spec around, but the number 1.1k-ohm sticks in my head?
Don't quote me on that...


-Ted

[JustJeff]

Originally Posted by RETed

Yes, coolant on the spark plug tips will kill them in short order.

You can do a quick & dirty test with a DMM...
Measure resistance from the spark plug wire end to the center electrode (in combustion chamber).
Check this same measurement on one of the brand new spark plugs.
The used spark plug should be *less* in resistance due to the center electrode wear down slightly.
If the spark plug is "fouled", the resistance is going to be significantly higher.
I forget what what these NGK BUR/EQ's spec around, but the number 1.1k-ohm sticks in my head?
Don't quote me on that...


-Ted

That's some pretty resourceful thinking. Plugs will be here Tues. and I'll get some measurements and report back.

[JustJeff]

Here's what I've got so far:

Haven't been able to accurately test my old spark plugs. Batteries in the DMM were low. It tested the new plugs just fine. All 4 9's tested at 4.83-4.91. But the old plugs I had all kinds of trouble getting readings. I was pulling old plugs and testing as I went. Wasn't getting good readings. Some of them the DMM was bouncing all over the place. Literally anything from "OL" to 35.00ish. I got frustrated with it, marked all the plugs for their position in the engine and came back to it later. While trying to test them again the DMM batteries died. I've got some batteries charging overnight and I'll test more tonight once I get home.

I moved the car to the location where I'm gonna pull the engine and looked some things over and generally tinkered around. I played around with my MBC settings to find out more about the stuttering when boost pressure builds. It always happens right when the engine goes from vacuum to boost. If I turn MBC all the way down and purging as much as possible stuttering happens less. What I found is that if I get the engine past that transition from vacuum to boost it boosts just fine once it gets beyond that point. If I turn the MBC up and get on the engine some pressure moves past that zero transition point quickly and once it's showing boost it will hold 5 psi nice and even. Going in the opposite direction when boost is dropping and its going back into vacuum the engine will again stutter. Vacuum leak is what I'm thinking?

Here is what I found. The two large vacuum hoses on the Purge Control Valve have turned soft and jelly-like and literally won't stay on the PCV. I have removed as much of the vacuum routing as possible but left the rats nest in place. I don't think I routed anything incorrectly...but user error is always possible. Going on the assumption that everything is routed correctly; my question is why those vacuum lines have turned to jelly? Oil blowing through the hoses?

Possibly related and possibly just normal behavior. When I first turned the rebuilt engine over and letting it idle, warm up, etc. I was checking fluids and listening for bad noises. I noticed my oil filter got amazingly hot. Too hot to touch and I was worried enough that I shut the engine off. I couldn't find anything out of place so I went ahead and proceeded with breaking in the engine and I haven't noticed the oil filter or oil temps being unusually high. I've got an aftermarket oil temp gauge and the numbers stay in the normal range.

[Pete_89T2]

Originally Posted by JustJeff

Here is what I found. The two large vacuum hoses on the Purge Control Valve have turned soft and jelly-like and literally won't stay on the PCV. I have removed as much of the vacuum routing as possible but left the rats nest in place. I don't think I routed anything incorrectly...but user error is always possible. Going on the assumption that everything is routed correctly; my question is why those vacuum lines have turned to jelly? Oil blowing through the hoses?

Possibly related and possibly just normal behavior. When I first turned the rebuilt engine over and letting it idle, warm up, etc. I was checking fluids and listening for bad noises. I noticed my oil filter got amazingly hot. Too hot to touch and I was worried enough that I shut the engine off. I couldn't find anything out of place so I went ahead and proceeded with breaking in the engine and I haven't noticed the oil filter or oil temps being unusually high. I've got an aftermarket oil temp gauge and the numbers stay in the normal range.

WRT the PCV hoses, the two hoses on the bottom of the PCV often turn to goo. That would be the large diameter one that goes to the oil filler nipple on the housing and smaller one routes back to the intake mani via the rats nest IIRC. Both see crankcase/oil vapors, so over time a cheaper grade rubber hose (regular vacuum hose) or a standard unlinered silicone hose will breakdown. Look for hose rated as an "emissions" hose to replace those; it's nitrile rubber IIRC, which is designed to be compatible with oil vapors.

The oil filter being too hot to handle is probably normal - depends on your threshold of pain. I've got an oil temp gauge on my FC, and if I touch the filter while the oil temp gauge is reading a normal 195F, I find the filter too hot to handle.

[JustJeff]

Originally Posted by Pete_89T2

WRT the PCV hoses, the two hoses on the bottom of the PCV often turn to goo. That would be the large diameter one that goes to the oil filler nipple on the housing and smaller one routes back to the intake mani via the rats nest IIRC. Both see crankcase/oil vapors, so over time a cheaper grade rubber hose (regular vacuum hose) or a standard unlinered silicone hose will breakdown. Look for hose rated as an "emissions" hose to replace those; it's nitrile rubber IIRC, which is designed to be compatible with oil vapors.

The oil filter being too hot to handle is probably normal - depends on your threshold of pain. I've got an oil temp gauge on my FC, and if I touch the filter while the oil temp gauge is reading a normal 195F, I find the filter too hot to handle.

Excellent point on the hose issue...I never even considered that.

About the filter, I didn't have my oil temp gauge wired up at the time I first started the engine up. My concern was how much hotter and how quickly it got hot compared to the rest of the engine and coolant. What I guess was going on was that there was probably air being pushed through with the oil on initial start up.

[Pete_89T2]

Originally Posted by JustJeff

Excellent point on the hose issue...I never even considered that.

About the filter, I didn't have my oil temp gauge wired up at the time I first started the engine up. My concern was how much hotter and how quickly it got hot compared to the rest of the engine and coolant. What I guess was going on was that there was probably air being pushed through with the oil on initial start up.

Compared to coolant, I've noticed my oil temps rise faster on a cold start. This is normal. The stock oil cooler has a thermovalve in it that allows oil to bypass the cooler when it's below a certain temperature. Also your oil filter has a pretty thin metal case, so the heat from the hot oil flowing thru it will readily transfer to your hand.

[RETed]

With the emissions hoses, you gotta be careful...
Anything that has oil (vapor) or gasoline vapor will make short order of regular "vacuum hose" and / or silicone vacuum hose.
In a pinch, I recommend using "carburetor fuel hose," which is cheap and easy to get from any car parts store.
At least the carb fuel hose is rated to handle petroluem liquids and vapors.
Almost any vacuum hose 6mm or 1/4" I.D. under the hood is going to have either oil "crankcase" vapors or gasoline vapors from the gas tank.

I concur that it's normal for the oil filter to get that hot.
For most humans, when temp start to edge over 100F, you tend to pull your hand away.
Pain threshold is around 120F - 130F?
I think 2nd degree burns start about that temps too.
Normal oil temps are 190F - 200F, so this is easily over the burn / pain threshold.
Coolant temps will beat oil temps to the thermostat setting, but the oil temps will tend to equalize faster throughout the engine due to 1) having a smaller heat exchanger - i.e. oil cooler, and 2) oil paths are concentrated around the hottest parts of the engine.
Once oil temps are at it's normal operating temperatures, it takes a long time for that temp to come down, especially versus coolant temps.

As for the MBC and boost sensor related issues...
I got a quick&dirty test for you, but with the engine being hurt, we might wait till after the rebuild?
You can isolate if it's a boost related issue by disconnecting the electrical connector from the boost sensor.
Try to minimize running the engine into heavy boost at any one single time, but running in and out of boost just across the "0" threshold should be safe.
If the hiccup goes away, it's a boost or boost sensor related issue.
If the hiccup is still there, look else where...


-Ted

[JustJeff]

Yeah, you two are both probably right abou the filter getting hot as quickly as it did. And being my first rebuild I'm looking for things and not knowing everything to look for...so I'm creating more questions that I need to.

I believe the car is parked where it will remain until rebuild is done. I'm probably done testing things after today. I'm getting a little crunched for time and like Ted mentioned, testing on a sick engine isn't really helping to narrow down any problems outside of the coolant seal problem. I did a compression test on the cold engine just looking for and hoping to get all even bumps. Which I did get!! Perfect world I would have warmed the engine up but that did not happen and I was really just easing my paranoia that my problems could also be related to a bad apex, corner or side seal.

Cold Numbers
Front 95-100ish
Rear 110-120ish all around

[JustJeff]

Well I believe while prepping the engine for removal I found the cause of my boost problems.


It was very small when I started removing things, In the process of pulling the TMIC and getting the pic I made the tear much much worse. The $4 plumbing coupler served me well, but I suppose I should get the proper part.

I haven't decided whether to pull the tranny with the engine or just the engine. Pulling the engine only will make removal much easier as I will not have to drain the transmission, lower the exhaust, remove heat shielding to get to transmission mount and convertible transmission brace. Come to think of it, I won't have to take the clutch hose off either.

Ted something I forgot to mention in our PM. On the initial rebuild I had replaced the clutch with an ACT street clutch. Replaced the throwout and pilot bearings at that time.

[Pete_89T2]

Originally Posted by JustJeff

Well I believe while prepping the engine for removal I found the cause of my boost problems.

It was very small when I started removing things, In the process of pulling the TMIC and getting the pic I made the tear much much worse. The $4 plumbing coupler served me well, but I suppose I should get the proper part. .

That will do it... For replacement silicone couplers & related parts, you might want to give these guys a try:

http://www.siliconeintakes.com/

Prices are very reasonable for silicone parts, and the parts I tried seem to be holding up rather well after a year of use on my daily driver. Haven't used any of their parts on the FC yet, but I purchased a couple of straight coupler pieces from them for my Protege5. The stock rubber/plastic intake pipe on that car has a bad habit of cracking over time, so rather than paying Mazda the crazy cost of another stock part, I fabbed up a replacement pipe with these couplers and some AL pipe.

Originally Posted by JustJeff

I haven't decided whether to pull the tranny with the engine or just the engine. Pulling the engine only will make removal much easier as I will not have to drain the transmission, lower the exhaust, remove heat shielding to get to transmission mount and convertible transmission brace. Come to think of it, I won't have to take the clutch hose off either.

My $0.02 is on pulling just the engine. If you're pulling the tranny out with it, you'll also need a bit more clear workspace in front of where the car sits to manuever the hoist & engine/tranny unit out of the car without hitting anything along the way.

[JustJeff]

Thanks for the heads up on silicone parts source. I did pull just the engine, and yes it was so much easier than pulling the tranny with the engine. Prepping for removal aside, it took maybe 15 min to pull the engine, swing the engine hoist around and drop the engine into the back of my van. Going to rebuild the engine in a warmer location than where the car is stored.

This might be mundane but the bolt from tranny to engine. The one behind the starter came out with oil on it. There wasn't a trail of oil leading down to the bolt (like from the oil filter area), and no oil around the head of the bolt. But I pulled the bolt out and it had a nice coating of oil on it.


There she is, in all her glory...

[RETed]

Originally Posted by JustJeff

This might be mundane but the bolt from tranny to engine. The one behind the starter came out with oil on it. There wasn't a trail of oil leading down to the bolt (like from the oil filter area), and no oil around the head of the bolt. But I pulled the bolt out and it had a nice coating of oil on it.

I swear it looks like oil dripped down from the oil filter / base?

Any leaks on the oil pan itself?
It could be an oil leak could've seeped upwards?


-Ted

[JustJeff]

Originally Posted by RETed

I swear it looks like oil dripped down from the oil filter / base?

Any leaks on the oil pan itself?
It could be an oil leak could've seeped upwards?


-Ted

Yes and yes, I'm using an oil pedestal sandwich for my temp and pressure senders. I did initially have problems with the sandwich leaking, which I had addressed. I also had a leak at the oil level sensor on the oil pan. I wasn't sure if the sensor that came on my JDM engine was working or not so I swapped to a known working one. I did not think to replace the oring and had a consistent but small leak from there.

I didn't not see any oil had run down the bellhousing of the transmission, but I think I know where this is leading. Oil from the pedestal leak worked its way between the rear iron and transmission?

[JustJeff]

How much should this soot bother me coming off the front exhaust port? I inspected the exhaust manifold and didn't see any cracks in that location.


Here is the port with a lil bit of soot matching the soot one the opposite facing of the gasket.