4.0 OHV Trouble Starting

[Mordecai]

Hey guys,
Recently have had trouble starting, especially cold starts.
The engine cranks 5-10 seconds before it starts, but the truck runs absolutely fine once it’s started. I have noticed I’m using a little coolant, and a very slight burning smell is present when I get out after the truck is off. The only other issue I might add, the Explorer seems a little lacking in power. New plugs and wires, oil change, air filter, maf, Iac, ect sensor, upper intake manifold gaskets, all within the last year.
I’m thinking it has to do with fuel delivery, or it’s the lower intake manifold gaskets that need replacing.
Any advice would be appreciated!

 

[Fix4Dirt]

yoiuve got the OHV correct? im wondering if between coolant consumption and lacking in power, if heads are cracked or its got a head gasket leak. was it ever overheated? if some coolant gets in the chamber it may take a bit to burn it off

 

[Mordecai]

yoiuve got the OHV correct? im wondering if between coolant consumption and lacking in power, if heads are cracked or its got a head gasket leak. was it ever overheated? if some coolant gets in the chamber it may take a bit to burn it off

Yep, got the 4.0 OHV. Not overheated to my knowledge, but I’ve only owned it for a year or two now. Relatively low mileage for the age, so I was hoping it wasn’t a serious problem.

 

[Fix4Dirt]

hmmm... it could be soemthing like low fuel pressure, but cuple that with coolant loss, and i would suspect its heads or head gasket........ getting it smogged soon? (not sure IL's smog stuff...) that may turn up some results if its there

 

[Mordecai]

hmmm... it could be soemthing like low fuel pressure, but cuple that with coolant loss, and i would suspect its heads or head gasket........ getting it smogged soon? (not sure IL's smog stuff...) that may turn up some results if its there

Is there any tell tale signs of heads going on the OHV engine, besides white material on the radiator cap and the symptoms I have?

 

[Fix4Dirt]

i dont own an ohv, but to my knowledge
1. moistrure on filler cap
2. moisture on pcv valve
3. if coolant shows up in oil analysis
4. compression test
5. occasioanl misfire
6. cracked insulator on spark plug
7. temp gauge swing
8. pressurizing cooling system on a cold motor, and to see if there is any decrease in pressure, although it would be minute
9. cold start idle issues

usually it cracks between the valve seals

a BANDAID, i emphasize bandaid, dont just pour. a gallon of this stuff in, but many have had success with KSeal as a coolant additive to seal the leak without clogging the system with the sand looking stuff that conventional sealants use. it stays suspended in fluid iirc. this aint a permanent fix obviously, but if it works, power to you! one thing to try before pulling heads and putting new ones on.

 

[Runnin'OnEmpty]

Is there any tell tale signs of heads going on the OHV engine, besides white material on the radiator cap and the symptoms I have?

One thing to look for is bubbles in the coolant reservoir when at operating temperature.

 

[410Fortune]

Check the engine
Block with a flashlight. Many lower intake coolant leaks or head gasket leaks will result in residue on the engine at the mating surfaces

Light coolant loss and sweet smell could be lower intake leaking for sure
Also could be head gaskets

Lower intake Re seal is a good idea
After that there are some head gasket sealants can be put in the coolant to buy time for a seeping head gasket. Must use the good sealant here! I would do lower intake first.

There is not a 4.0 pushrod out there that does not need new/ updates lower intake gaskets… these engines are now 20+ years old and those gaskets simply do not last this long

 

[fast_dave]

I have noticed I’m using a little coolant, and a very slight burning smell is present when I get out after the truck is off.

@Mordecai

The details in your post tell the story of a 4.0 OHV daily driver starting to have cooling problems that will only get worse (ask me how I know).

If all of a sudden you're having a hard time starting in the mornings, are watching & marked your overflow tank level and note that you're using/losing coolant AND smell the sweet smell of coolant burning from your exhaust when your Ex is running, you have a pretty substantial issue that is coolant related.

IMO - 26 year old head gaskets are the 1st weak point, followed by micro-cracks in the head(s).

The last step in the cooling system degradation that will affect a full on engine failure/un-drivability will be that you will get a misfire followed by bucking/shuddering while driving.

More than likely that final step will occur as we get into hotter seasonal temps.

HTH -