4.2 sudden problems
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4.2 sudden problems
Hello all. I am very new to this site and have read several posts on problems with the 4.2. I have not really had any problems since I bought mine (98' STX 4.2) new 123K miles ago until now. I went to start it after a dentist visit (so it was not a complete cold start) and it turned then stopped but I could hear what i thought was the starter still spinning. Tried again and called someone for a jump. When I checked the cables the negative was VERY hot. Enough to leave a blister on my thumb. Got it going again and have had this same thing a couple times but it does start. Oh yeah replaced the battery that same day. SInce then I have noticed that when I first start it there is alot, and I mean ALOT, of gray smoke would billow out and it would run rough until it got warm. Then both the smoke and roughness would stop? I also had a #1 misfire pop up, which I think I found the problem to that with the plug wire. Anyway, I do lose coolant but that is due to a leaking freeze plug I need to replace but nervous as heck to attempt!!! ANy clues on this come and go smoke? I'm thinking something is sticking but not sure what or why. Any inputs will be appreciated.
Thanks in advance
Dale
Thanks in advance
Dale
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Joined: Aug 2001
Posts: 4,532
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From: Trussville, Alabama
Dale,
It sounds very much like you have a bad lower intake manifold gasket which is leaking coolant into one or more cylinders after you shut the engine off.
But, there are a few things that don't add up completely to = lower intake gasket, like thinking you still hear the starter spinning ??
You already know you are losing coolant, but you might also check the oil to see if it has any sign of coolant mixed in.
A leaking manifold gasket might- or might not - result in hard starting, smoke, misfiing, etc.
It all depends where the pistion is in the 4 stroke process.
If the cylinder in question is on the exhaust stroke, it just blows the coolant right out the exhaust when you turn the key to start.
If the piston is on the compression stroke, it can stall the starter, or if the battery/starter are strong, break a connection rod, break a piston, etc. (the results of hydrolock)
If you like your truck and want to keep it running - i'd get it checked SOON.
A compression/leakdown test should lead to a firm diagnosis.
FWIW, I had a 2000 that needed the lower intake manifold gasket at 155,000 miles.
Parts, labor, bead blasted inside of intake, new T-stat, and a few other misc things, It was just a little over $400 at a good local independant shop.
I fear if you push your luck, you'll likely ruin your motor.
It sounds very much like you have a bad lower intake manifold gasket which is leaking coolant into one or more cylinders after you shut the engine off.
But, there are a few things that don't add up completely to = lower intake gasket, like thinking you still hear the starter spinning ??
You already know you are losing coolant, but you might also check the oil to see if it has any sign of coolant mixed in.
A leaking manifold gasket might- or might not - result in hard starting, smoke, misfiing, etc.
It all depends where the pistion is in the 4 stroke process.
If the cylinder in question is on the exhaust stroke, it just blows the coolant right out the exhaust when you turn the key to start.
If the piston is on the compression stroke, it can stall the starter, or if the battery/starter are strong, break a connection rod, break a piston, etc. (the results of hydrolock)
If you like your truck and want to keep it running - i'd get it checked SOON.
A compression/leakdown test should lead to a firm diagnosis.
FWIW, I had a 2000 that needed the lower intake manifold gasket at 155,000 miles.
Parts, labor, bead blasted inside of intake, new T-stat, and a few other misc things, It was just a little over $400 at a good local independant shop.
I fear if you push your luck, you'll likely ruin your motor.
Last edited by BrianA; Dec 17, 2006 at 05:38 PM.
Cargo Master
Joined: Aug 2002
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From: Cajun Country
Replacing a freeze plug is easy,as long as you have good access to it.Drain the coolant.Use a blunt object to knock one side of the freeze plug into the block.Grab it with some channel locks and pull it out.Clean the area where the new plug is to be installed.Apply some RTV to the freeze plug.Use a socket smaller then the inside of the freeze plug,and drive it in until the edge is about 1/16" into the block hole.Apply more RTV to the edge of the plug.Refill with coolant and check for leaks.Simple,huh? 
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Thanks for the inputs. Right after I wrote my post the truck stopped smoking. It now has a distinct tapping sound while warming up. This happened to me a while back and since I thought sticking valve or something I did teh engine flush deal, which cleared it uo until now. Personally I think the two are related since I thought the smoke just going away after it warmed up was something sticking, and now the tapping clears up in about the same amount of time. I checked the oil for signs of coolant but found nothing. Also teh plug is very easy to get to and I think I will get this done right away so I can be sure I'm not losing coolant anywhere else. Thanks for the input(s) and I welcome anything else you guys want to inform me on. My degree is in electronics, not automotive so the more info I have the better off my truck and I are...
Thanks again
Dale
Thanks again
Dale
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Joined: Aug 2001
Posts: 4,532
Likes: 5
From: Trussville, Alabama
FWIW, there have been a few cases of broken rocker arm, so keep that in mind as you chase the culprit.
A mechanics stethascope (or a 3-4 foot piece of rubber hose) can go a long way in isolating the exact source of the noise.
Does the tapping seem to be coming from the bottom end (crank,rod bearing) or the top end of the engine (valve train) ?
Best of luck and keep us posted.
A mechanics stethascope (or a 3-4 foot piece of rubber hose) can go a long way in isolating the exact source of the noise.
Does the tapping seem to be coming from the bottom end (crank,rod bearing) or the top end of the engine (valve train) ?
Best of luck and keep us posted.
Last edited by BrianA; Dec 19, 2006 at 10:28 PM.
Cargo Master
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From: Cajun Country
Something else to consider;aftermarket oil filters do not have the same anti-drain back valve installed in there oil filters like the factory Motorcraft does.At start up this can cause a ticking sound as the filter is starved for oil. 
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Thanks again for all the replies. The sound seems to be coming from the top, although when I put the scope on the drivers side exhaust I can hear it there too? Would a broken rocker arm stop tapping when the engine got warm? I tried the flush again today but it still is there. Didn't know about the oil filter problem? The problem I have is I simply don't have the time to look into it much less fix it. We are woking 5-6 12hr days, and I'm afraid it's just going to drop out if I keep putting this off. How do you check for these problems using the least amount of time and disassembly? Tough question I know but any help will be appreciated. Also could it be something in the exhaust? Again thanks in advance.
Dale
Dale
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Cargo Master
Joined: Aug 2002
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From: Cajun Country
Do you know any mechanics,that you trust? Or,a Ford dealership? If you're working those long hours and can't fix it,your next choice is to have someone look at it.In the past when I worked hours like that I would let my local Ford dealer work on mine;but,I trust them!
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Joined: Mar 2005
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From: uk
dale, i would go with briana in regards to lower intake and timing cover gasket failure. you have all the symptoms. the coolant will not show-up on the dipstick due to it sinking to the bottom of the sump.
i chased the noises long enough to knock-out the crankshaft bearing and that inclueded 3 oil changes and addatives etc.
the big telltale is the white smoke and the sweet smell of antifreeze.
you sound like the gaskets have just started to breakdown so do not take any further chances and get it checked. good luck bokker.
i chased the noises long enough to knock-out the crankshaft bearing and that inclueded 3 oil changes and addatives etc.
the big telltale is the white smoke and the sweet smell of antifreeze.
you sound like the gaskets have just started to breakdown so do not take any further chances and get it checked. good luck bokker.
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Originally Posted by BrianA
FWIW, there have been a few cases of broken rocker arm, so keep that in mind as you chase the culprit.
A mechanics stethascope (or a 3-4 foot piece of rubber hose) can go a long way in isolating the exact source of the noise.
Does the tapping seem to be coming from the bottom end (crank,rod bearing) or the top end of the engine (valve train) ?
Best of luck and keep us posted.
A mechanics stethascope (or a 3-4 foot piece of rubber hose) can go a long way in isolating the exact source of the noise.
Does the tapping seem to be coming from the bottom end (crank,rod bearing) or the top end of the engine (valve train) ?
Best of luck and keep us posted.
Senior User
Joined: Mar 2005
Posts: 352
Likes: 1
From: uk
hi, thats some pressure that can distroy a piston in that manor, it must have been at the bottom of its stroke and full of coolant, valves tight shut and a damn good starter motor. sorry to hear about your problem.
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