My Jeep doesn't like the Cold

[Scout1067]

Here are a couple of questions. My CJ is my daily driver and over here in Germany we are now at the part of the year where we get frost every night. My Jeep is parked outside, the wife refuses to give up the garage because she is mean.
Two weird things have started happening since it got cold. I have the AMC 258 i6 / 4.2l with a Weber carb and square box air filter on it, and the T-176 tranny.

1. When I first start it in the morning the even with the clutch depressed completely the plates don't disengage completely until after I turn the engine over and the Jeep jumps a little. Could the cold be making the clutch plates sticky or is this a symptom of maybe water getting into the bell housing? It only does this if it dips below freezing overnight.

2. When it is really cold a high pitched whistling noise comes from under the hood until it gets to normal operating temperature. This one baffles me because even with the hood up I can't get a good idea of where the whistle is coming from. The engine runs fine, it just whistles until it warms up. My first though on this was a seal contracting from the cold but I can't see anything and its not losing vacuum in the carb.

Anybody have any ideas?

 

[gr8dain]

I read this to wife. She said you need to get a different car. She might be considered mean as well.

Are you able to put it in neutral before starting and not have an issue? I assume so. I have issues with starting in the cold as well. I blame the carb. I am going to switch to efi (Holley Sniper) soon. I have the whistle as well. I assume air is getting in somewhere until it warms up. I have checked the seal between the carb and intake. That seems fine. I am living with it.

Good luck.

 

[Scout1067]

I read this to wife. She said you need to get a different car. She might be considered mean as well.

Are you able to put it in neutral before starting and not have an issue? I assume so. I have issues with starting in the cold as well. I blame the carb. I am going to switch to efi (Holley Sniper) soon. I have the whistle as well. I assume air is getting in somewhere until it warms up. I have checked the seal between the carb and intake. That seems fine. I am living with it.

Good luck.

It starts right up. Converting to manual choke made a huge difference in that regard. I can put it in neutral and it rolls so I am not really sure what is going on with the clutch. I have new clutch plates and a flywheel but I was going to wait to put them on until the clutch started slipping, which it doesn't do. On thing the tranny does is shift really hard when it's cold. It is not difficult to switch gears but it really thunks when I let off the clutch until it warms up.

The whistle doesn't really concern me that match because it doesn't seem to affect the way it runs, it mainly just sounds goofy I think. I would still like to figure it out though.

 

[Torxhead]

I would think that an engine block heater might help.

 

[Lumpy Grits]

The 'whistle' is a vacuum leak of some sort.
The clutch has not one thing to do with starting in cold weather unless you have been in deep water.
Are you losing coolant?
What weight oil do you have in the engine?
LG

 

[Scout1067]

The 'whistle' is a vacuum leak of some sort.
The clutch has not one thing to do with starting in cold weather unless you have been in deep water.
Are you losing coolant?
What weight oil do you have in the engine?
LG

In answer to your questions.

I figured it is a vacuum leak but am not sure I should be too concerned as it goes away after about 3-5 minutes as soon as the engine starts heating up. I am guessing that a gasket or hose is shrinking a little due to the cold and the leak stops as soon as it heats up and expands back to normal size.

No, I am not losing coolant. I thought to check that as well.

I am running synthetic Valvoline 5W-30 for high mileage engines. The oil level is correct and other than being a little black because I am due for an oil change in another 1500 miles it looks good.

 

[Lumpy Grits]

How cold does it get(degrees)where you live?
You need to fix that vacuum leak, as I'll bet it's part of the issue.
Check all the intake and exhaust manifold bolts nuts etc.
LG

 

[Scout1067]

How cold does it get(degrees)where you live?
You need to fix that vacuum leak, as I'll bet it's part of the issue.
Check all the intake and exhaust manifold bolts nuts etc.
LG

In January-February it can get down to the single digits. Today it was in the 20s when I left for work but no whistle. I imagine I will have fun chasing the leak down. The manifold bolts should be good as I had to replace the manifold gasket last spring and the bolts and gasket are new. I will double check it.

I started leaving it in neutral and chocking one wheel overnight and have had no more issues out of the tranny. I am worried about the parking brake freezing when it gets real cold.

 

[cglax6]

I started leaving it in neutral and chocking one wheel overnight and have had no more issues out of the tranny. I am worried about the parking brake freezing when it gets real cold.

That's really interesting. Almost sounds like you're getting enough condensation and then freezing the clutch to the flywheel. Does the shudder still happen if you leave it in gear overnight and then shift to neutral before starting? If it does, you may have something wonky happening inside the Transmission .

How old is the clutch?

Do you have a mechanical clutch or hydraulic? Either way, I'd check your system.

When you leave it in gear, do you notice the clutch pedal going all the way down like it normally does, or does it seem to stop short?

I don't know if you're going to be able to tell exactly what's going on unless you're able to take a look inside the bellhousing if everything else seems normal.

 

[Lumpy Grits]

How hot in the summer does it get?
Thinking you could go with a 10W-30 or maybe a 10W-40 engine oil.
Check those manifold bolts ASAP.
The whistle could be the manifold heating up and expanding to seal.
LG

 

[Scout1067]

That's really interesting. Almost sounds like you're getting enough condensation and then freezing the clutch to the flywheel. Does the shudder still happen if you leave it in gear overnight and then shift to neutral before starting? If it does, you may have something wonky happening inside the Transmission .

How old is the clutch?

Do you have a mechanical clutch or hydraulic? Either way, I'd check your system.

When you leave it in gear, do you notice the clutch pedal going all the way down like it normally does, or does it seem to stop short?

I don't know if you're going to be able to tell exactly what's going on unless you're able to take a look inside the bellhousing if everything else seems normal.

Yeah, there is some clutch shudder when switching gears until the engine heats up. I have new clutch plates, just haven't put them on. That is a project I was going to tackle in the spring. I put on new suspension tomorrow and to be honest I don't even know when i would have time to drop the tranny and bellhousing. I am leaning towards the idea that there is water getting in there but you are right, until I open it up I probably won't know what is really going on.

How hot in the summer does it get?
Thinking you could go with a 10W-30 or maybe a 10W-40 engine oil.
Check those manifold bolts ASAP.
The whistle could be the manifold heating up and expanding to seal.
LG

Checked the manifold bolts last night with a torque wrench and they are good. It looks like there is a little oil seepage around the head cover. Summers here get into the mid-80s, it is rare for it to get hotter than that. I go with the 5W-30 because it tends to stay way cooler here in Germany than in TX/OK where I lived in the States. Ironically, it was even colder yesterday, low 20s, but there was no whistle. I wonder if I am chasing a gremlin here.

 

[Lumpy Grits]

Check the carb mounting nuts.
Also the exhaust manifold, where it bolts to the exhaust pipe.
Please confirm the temps you give me are in degrees and not 'C'.
FWIW: I run Castrol Hi-mileage 20W-50 year-round and we will see low 20's in Winter to 110* in the summer.
The hydraulic tappets seem like the thicker oil.
LG

 

[Scout1067]

Check the carb mounting nuts.
Also the exhaust manifold, where it bolts to the exhaust pipe.
Please confirm the temps you give me are in degrees and not 'C'.
FWIW: I run Castrol Hi-mileage 20W-50 year-round and we will see low 20's in Winter to 110* in the summer.
The hydraulic tappets seem like the thicker oil.
LG

Yes, the degrees are in Farenheit. I have been over here for a combined 18 years and still can't wrap my mind around Celsius. My wife thinks it's hilarious that I still convert the temps in my head when we watch the weather. I am good with Km because everything in the military is meters and KM.

I checked the manifold bolts and they are all in spec according to the torque specs in the FSM. I had not thought about the carb mounting bolts themselves. I will check that today since i am taking it to the Auto Skills center on post today to replace the suspension. I will also put the vacuum gauge on and see if I can figure out the leak. Thanks again for your patience in helping me troubleshoot this LG.

 

[Lumpy Grits]

PLZ keep us updated.
FWIW; My Mother's family came from Germany after WW1. Last name was Haan.
LG

 

[Scout1067]

PLZ keep us updated.
FWIW; My Mother's family came from Germany after WW1. Last name was Haan.
LG

Checked the carburetor mounting bolts and they are all tight. Oddly, the whistling has stopped even though the weather has stayed cold. It's a head scratcher. The tranny still jumps until it warms up but I have not split the bell housing to see if water is getting in or not. Probably wont do that until after the holidays.

 

[Lumpy Grits]

Check your engine and tranny mounts to be sure they are intact.
Check your clutch linkage for wear at the pivot points.
LG

 

[Scout1067]

Check your engine and tranny mounts to be sure they are intact.
Check your clutch linkage for wear at the pivot points.
LG

Engine and tranny mounts are solid. That is one of the things I checked before bidding on the Jeep last spring. I cant see any odd wear on the clutch. My gut says it is the clutch pads and plate. I have replacements I was just hoping to not have to put them in until after the winter.

 

[cglax6]

My gut says it is the clutch pads and plate. I have replacements I was just hoping to not have to put them in until after the winter.

I'm almost thinking the same thing. Maybe the rivets in the clutch pad are failing and expanding and contracting in the change in temp? Or there's something just barely off in the clutch linkage that doesn't allow the throwout bearing to move as far as it needs to when everything is cold. But that doesn't make sense because the engine wouldn't warm those pieces up enough to make that much of a difference. Maybe worn out diaphragm springs or torque springs in the clutch plate.

Just tossing out ideas...

Either way, I think it's going to come down to replacing the clutch. I'd say no rush as long as everything is ok after you're warmed up, or if it doesn't get any worse.

I don't have a nice garage to work in, so I hate working on mine in the cold. fingers get numb quick handling cold metal. Sucks the heat right out of you.

The more I think about it, the more unlikely I think that ice is the culprit.

 

[Lumpy Grits]

If the issue goes away after warm up-It's something else.
Did you check the clutch linkage for wear like egg shaped holes and sloppy bellcrank etc?
How much clutch pedal free travel do you have? You want no less than 1" and no more than 1 1/2" max.
LG

 

[Scout1067]

I don't have a nice garage to work in, so I hate working on mine in the cold. fingers get numb quick handling cold metal. Sucks the heat right out of you.

Yeah, I don't have a nice garage to work in either. I think working on a car in an icy driveway is somehow worse than tooling along in ice fog in the BC's hatch of a Bradley in a Balkans winter. Luckily, there is an auto skills center with nice heated bays on post that I can take it to. I still try to put off most work until the arm months if I can.

If the issue goes away after warm up-It's something else.
Did you check the clutch linkage for wear like egg shaped holes and sloppy bellcrank etc?
How much clutch pedal free travel do you have? You want no less than 1" and no more than 1 1/2" max.
LG

I checked the clutch linkage when I bought it in May and it was good then. My clutch pedal free travel is right on FSM spec. Interestingly, the FSM says that it could be the pilot bushing. This is the relevant section from page 2A-7 of the FSM for my year CJ7

"Crankshaft Pilot Bushing Noise
Pilot bushing noises can be described as squealing, howling, or elephant-type trumpeting noises which are most when the engine is cold. These noises occur during the first few inches of clutch pedal travel as the pedal is being released (partial clutch engagement) with the Transmission in gear. It can also occur in very cold weather when the pedal is fully depressed (clutch disengaged) and the engine is started with the Transmission in neutral. To correct pilot bushing noise, replace bushing as outlined in this section."

I really don't want to have to do a clutch job in the middle of winter.