1999 Mountineer Starting Violently

[terkldriver]

My mother in-law owns a 1999 Mercury Mountineer 4.0 SOHC AWD. It has a problem, where, when it starts up cold, it revs really high, and has a slight rod knock. When it starts warm, it doesn't have this issue. I had an oil pressure issue a while ago, which turned out to be the sensor for the dummy gauge on the dashboard. I've also done some searching as well. I'm a car guy, so I know what I'm doing, once I've diagnosed the issue....

Thanks in advance!

John

 

[2000StreetRod]

leaking intake manifold gaskets

The cold start engine flare on the SOHC V6 is often due to leaking intake manifold gaskets. They shrink with age and cold. I suggest that you consider installing the 00M12 kit.

 

[Gloff]

Check the coolant level and radiator, mine did that when my radiator was leaking at the plastic. Cold starts would rev to about 1700, Ford Tech said when the coolant gets low the sensor in the engine sees that there is less coolant and compensates as if it were cold.

 

[McSlug]

Does the idle fluctuate or just stay high?

My idle would fluctuate from 600 rpm to almost 2500 rpm back to 600 rpm almost stall and rev back to 2500 rpm in a continuous cycle for 10 minutes before I replaced the upper and lower intake gaskets. This is not good when the engine is cold, the oil is still in your sump and you have faulty timing components fitted.

The rod knock you hear may actually be timing chain related. Have you tried to diagnose this very common issue. It can be any one of the 4 timing chains, their guides or their tensioners.

Good thing your a car guy and I hope you like your mother in law. You might be spending a bit more time with her.

 

[terkldriver]

Timing chains make alot of sense. I've heard very terrible things about those specifically on these trucks. I just really don't like the sound that it makes...just really nasty and sounds like it's eventually going to hurt the motor in the truck. I'm going to check the coolant level, that's the easiest solution, also the fact that I just had to flush the radiator due to the fact that the coolant was straight BLACK...no oil, just black.

Idle stays normal, never trys to stall...ever. Just that first inital startup when it's dead cold. I talked to some of my buddies who are all Mustang guys, they said the intake issue sounds about correct, timing chains make more sense, just because of the type of sound it's making. Is there anyway to check the timing issue without pulling to many covers off the front of the truck?

Also, where do I find the 00M12 kit? Intake manifold issues are MUCH easier to deal with then timing issues. Also, the truck sat for a long time without being driven. They bought the truck new in 2000 and it has a grand total of 70k on the clock. which would again, point to the intake manifold gaskets leaking.

I don't mind her at all....haha I built had built my 91 Explorer with a 10in lift on 37's at her house, and my Boosted 1994 Tercel's home, is in her garage....which I also built at the house too. Thanks for all of your help too!

 

[2000StreetRod]

00M12 kit

00M12 intake manifold kit YL2Z9E473AA
You can buy it online from tousleyfordparts.com

See My Helpful Thread:Starting my 00M12 Installation

 

[McSlug]

Check the coolant level and radiator, mine did that when my radiator was leaking at the plastic. Cold starts would rev to about 1700, Ford Tech said when the coolant gets low the sensor in the engine sees that there is less coolant and compensates as if it were cold.

Great tip! I have not heard this one! Another piece of ammo for trouble shooting.

 

[McSlug]

Timing chains make alot of sense. I've heard very terrible things about those specifically on these trucks. I just really don't like the sound that it makes...just really nasty and sounds like it's eventually going to hurt the motor in the truck. I'm going to check the coolant level, that's the easiest solution, also the fact that I just had to flush the radiator due to the fact that the coolant was straight BLACK...no oil, just black.

Idle stays normal, never trys to stall...ever. Just that first inital startup when it's dead cold. I talked to some of my buddies who are all Mustang guys, they said the intake issue sounds about correct, timing chains make more sense, just because of the type of sound it's making. Is there anyway to check the timing issue without pulling to many covers off the front of the truck?

Also, where do I find the 00M12 kit? Intake manifold issues are MUCH easier to deal with then timing issues. Also, the truck sat for a long time without being driven. They bought the truck new in 2000 and it has a grand total of 70k on the clock. which would again, point to the intake manifold gaskets leaking.

I don't mind her at all....haha I built had built my 91 Explorer with a 10in lift on 37's at her house, and my Boosted 1994 Tercel's home, is in her garage....which I also built at the house too. Thanks for all of your help too!

Ford changed the type of rubber the intake gaskets where made of. When they did this I don't know. You may have the new type. How long they last I don't know either. Anyone have an answer for this?

If there is nothing wrong with the rear chain or cassette leave it and pray. It is not as prone to failure as the front.
As for the front cassette and primary tensioner they are faulty by design and one or both will fail. I'd wager my left ******** on that. From the sounds of it the front cassette is probably already in pieces. It can run like this for some time spreading plastic through out the system.

If you are going to do the OOM12 kit you may as well replace the front timing components. Everything you remove for the OOM12 you will need to remove to do the timing.