smoking 4.6L Ford typical cause?

[3 Mad Ponchos]

My brother's '94 Grand Marquis has a 4.6L that smokes when under load (pulling away from a light, accelerating to pass, etc). I know the 4.6L has a history of oil burning, but not being much of a Ford guy, I can't recall the cause. Anyone here know?

Cheers, 3MP

 

[boxcartommie22]

the 4.6 and 5.4 has no history of oil burning same as the 302 if one takes care of them..these engines are one of the best engines of them all..

 

[Whimsey]

I believe that some of the early years 4.6L Ford engines has "issues" with valve guides which caused oil burning. Maybe an autorx treatment is due. It can't hurt, only help.

Whimsey

 

[MRC01]

quote:

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Originally posted by 3 Mad Ponchos:
My brother's '94 Grand Marquis has a 4.6L that smokes when under load (pulling away from a light, accelerating to pass, etc). I know the 4.6L has a history of oil burning, but not being much of a Ford guy, I can't recall the cause. Anyone here know?
Cheers, 3MP

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These engines are tight and typically don't consume oil unless there's something wrong. One case I'm aware of is guys who have installed headers, if they're not cleaned out before assembly, ceramic balls from the jet hot coating or loose weld slag can break free and enter the combustion chamber through the EGR and intake. This will score the cylinder walls and cause it to smoke. Only solution is to tear down & rehone / rering.

 

[MNgopher]

The smoking issue on the crown vic / grand marquis is well known. The issue is the Valve guide seals. I can't remember the eaxact year, but I believe on the 4.6 prior to 1996 is susceptible to the problem. Essentially the seals were made out of an inferior material and failed between 60k and 80k miles. Symptoms include light smoke on idling and large clouds of smoke when accelerating, especially after idling.

Repair is replacement of the valve guide seals. The new seals have cured the problem. An Auto-RX treatment may be worth a shot to see if it improves things.

Otherwise, these motors are not notorius oil users - generally ranges between no use and 1 qt every 3,000 miles. Anything more is abnormal.

 

[Jimbo]

This is one place where "high mileage" formula oil may be the ticket. If the valve guide seals are not too far gone, the seal conditioners may help delay the repair for quite a while.

 

[got boost?]

quote:

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Originally posted by boxcartommie22:
the 4.6 and 5.4 has no history of oil burning same as the 302 if one takes care of them..these engines are one of the best engines of them all..

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actually they DO have a history of the oil burning. both guides AND guide seals have been problems. if you do some research (with an open mind) I believe you will find that the 4.6/5.4 are poorly designed engines. ford designed them with such narrow bore spacing that the only way to increase displacement is by stroking them. the increased stroke (5.4) leads to high piston speeds and accelerations. the 351 was a much better engine (the 302 had a very weak block and rotating assembly from the factory).

 

[Jimbo]

How is the 302/351W that much different? The bore is the same and the 351 stroke is longer. Why an OHC design for a low-cost V-8? GM stayed with pushrods for the Vortec V-8 engines.

 

[got boost?]

the windsor engines had 4 inch bores and the modulars have ~3.5 inch bores. the 5.4 has a longer stroke (~4.1 inch) than the 351 (3.5 inch). ford has no way to increase displacement of the 5.4 liter, as the stroke is at the limit. other problems include very thin main supports (*yes they are six bolt, but still), and HUGE exterior size.

[ August 05, 2003, 06:12 PM: Message edited by: got boost? ]

 

[MNgopher]

So what if an engine can't be bored out for increased displacement. It has little to do with the reliability of an engine. Reality is the new motors are more efficent for the material they use than the old blocks. Reality is that the old motors were overbuilt for their intended purpose, thus the huge aftermarket for pulling more power out of them. Newer engines from all manufacturers are squeezing more out of less, thus leaving less tricks for the aftermarket. Does that make an engine less reliable?

The 4.6l in particular in a bulletproof motor. The 5.4 hasn't been around as long, but is getting a similar reputation among users. Yes, there have been problems along the way (piston slap and leaking head gaskets come to mind).

 

[3 Mad Ponchos]

Thanks guys, I appreciate the feedback on the oil-burning problem... regardless of how common it may be.

Cheers, 3MP

 

[FowVay]

3 Mad, I have two friends at my work that drive Ford trucks (F-150 and Excursion) with the 5.4 liter engine. Both of these vehicles consume oil at a rate of 1 quart per 2000 miles. I talked one of the guys into using Quaker State's High Mileage 10W-40 in his '99 model and this reduced his consumption considerably. He now does not need to add oil during his 3,000 mile drain interval. I'm trying to get him to go 5,000 miles and see if his trucks needs a quart of top-off within this interval.

I've worked on a few of the 4.6 liter engines and I like them even if they do use a bit of oil.

 

[3 Mad Ponchos]

Thanks, he's already running Valvoline high-mileage and it hasn't done any good. The blue smoke is just more expensive, LOL.

Cheers, 3MP

 

[NutBuster]

I've seen oil puff from a cobra, Puffs from a Licoln, puffs from a Grand Marquis, and puffs from a magic dragon. but seriously...

I recall sludging being a problem with oil consumption in older Ford V8 engines that were not well maintained. Small oil return holes in the head combined with sludge slowing the flow back to the pan caused many of them to smoke. I'm not sure if this is a problem in the modular fords since I have never needed to pull a valve cover off one. I recall the Mitsu-Chrysler 3.0 V6 engines had this problem as well.

Of course thicker oil will exacerbate the problem. It will pool up in the head and gets sucked through the valve guides.

I figure Ford will replace the modular soon since it's getting killed in the naturally aspirated horsepower wars...plus, the design is about 13 years old now. The LS1 is a baby compared to the modular, and now the new Hemi is here. If their 24 valve F150 modular won't compete with the Hemi in power, they need to just go back to the drawing board without delay or make superchargers the norm.

if Chevy can make over 400 HP with 16 valves and no supercharging in their V8, then I can't imagine what is getting in Ford's way. Somehow the F150 will continue to inexplicably outsell everything...and they'll keep costs low by not developing a competitive engine. I, however prefer to invest my money in current technology...and it looks like the future will have pushrods!

 

[mf150]

The new Modulars are comming next year from Ford. The 5.4L's are comming in 4v versions that will produce a higher HP.

As far as OHC engines, you can't beat them as far as dependability. HP is different than torque, and Ford can still out tow Chevy. The new Hemi, from what I've heard is a monster, but the Ford Powerstroke can out tow it anyday.

The Cobras are SC'ed, the Harley Davidson truck puts others to shame, and teh new lighning will give everyone a run for their money.

I don't think Ford will have a problem with marketing their new vehicles. For over 23 years now they've been number 1.

05 the mustangs will be re-designed.

My point, Ford is very much in the game. More so than before.

 

[eldawg4100]

seriously, I ALWAYS see grand marquid 4.6's blowing blue smoke off acceleration. sometimes 2 a day. But its by far the most seen car by me that blows blue smoke...

 

[MRC01]

quote:

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Originally posted by NutBuster:
I figure Ford will replace the modular soon since it's getting killed in the naturally aspirated horsepower wars...plus, the design is about 13 years old now. The LS1 is a baby compared to the modular, and now the new Hemi is here. If their 24 valve F150 modular won't compete with the Hemi in power, they need to just go back to the drawing board without delay or make superchargers the norm.

if Chevy can make over 400 HP with 16 valves and no supercharging in their V8, then I can't imagine what is getting in Ford's way. Somehow the F150 will continue to inexplicably outsell everything...and they'll keep costs low by not developing a competitive engine. I, however prefer to invest my money in current technology...and it looks like the future will have pushrods!

---

I don't wanna get sucked into yet another Ford vs. Chevy debate... BUT...

It's amusing to hear someone referring to an all aluminum high revving quad cam engine as "old fashioned" compared to an iron block low revving pushrod engine.

 

[got boost?]

quote:

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Originally posted by MRC01:

quote:

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Originally posted by NutBuster:
I figure Ford will replace the modular soon since it's getting killed in the naturally aspirated horsepower wars...plus, the design is about 13 years old now. The LS1 is a baby compared to the modular, and now the new Hemi is here. If their 24 valve F150 modular won't compete with the Hemi in power, they need to just go back to the drawing board without delay or make superchargers the norm.

if Chevy can make over 400 HP with 16 valves and no supercharging in their V8, then I can't imagine what is getting in Ford's way. Somehow the F150 will continue to inexplicably outsell everything...and they'll keep costs low by not developing a competitive engine. I, however prefer to invest my money in current technology...and it looks like the future will have pushrods!

---

I don't wanna get sucked into yet another Ford vs. Chevy debate... BUT...

It's amusing to hear someone referring to an all aluminum high revving quad cam engine as "old fashioned" compared to an iron block low revving pushrod engine.

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the ls1 is an aluminum block, and it has a much better high rev potential than the 5.4 modular. also the ls1 is a newer design totally different then the 350 (the ls1 is a 346).

 

[3 Mad Ponchos]

The LS1 is all-aluminum and redlines at 6200 rpm. If that ain't enough rpm for ya, go get an S2000.

Nuthin' wrong with pushrods if they get the job done.

Cheers, 3MP

 

[MRC01]

quote:

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Originally posted by 3 Mad Ponchos:
The LS1 is all-aluminum and redlines at 6200 rpm. If that ain't enough rpm for ya, go get an S2000.

Nuthin' wrong with pushrods if they get the job done.

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I got nothing against the LS1 engine. It's a great powerplant. However, the Ford is also a great powerplant and more modern in at least some aspects of its design: dual overhead cams, all aluminum block & heads, variable dynamic intake geometry, etc. Taching my V-8 to 7,000 RPM and having it pull hard all the way up puts a big grin on my face every time.