Plain Jane OEM nothing to see here rebuild

[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