Help me think this out.

uvbnhad · 03-29-2005, 09:48 PM

Unfortunately it looks as though Ford is going to screw me over on the issue I've been going through based on the bull shit LL created. Now I have to fix the car and I'm going to let Paul do it but I'd like to get a feel for what I'm facing.

Symptoms:
-Rough idle but smoothes throughout RPM band.
-valve chattering
-slight oil smoke from from exhaust
-noticable power loss from low RPMs but less as RPMs/speed increases.

Noticeable things:
-no rod/piston knocking - leads me to think there isn't any "severe" internal damage
-idle smooths - makes me think it's nothing more than a valve(s) opening/closing correctly --> also makes me think Exhaust valve.

Follow me on this and see if it makes sense. Exhaust valve is not closing opening correctly thus not allowing the cylinder to make the normal power; creating a rough idle as the engine is then off-balance. As the rpms increase, the engine doesn't rely on each individual cylinder as much per se. The collective power of the entire engine is greater than each individual cylinder; i.e., inertia.

Any thoughts? Am I flawed in my thinking? Another cause?

QWKSNKE · 03-30-2005, 04:46 AM

ok I am thinking that if it is a valve situation like you mentioned, that it is going to be rough at all rpms or at least noticable. Has anyone had the valve covers off and looked at the valvetrain?

Has the car been put on scanner to check for codes?

Sendero · 03-30-2005, 08:09 AM

Quote:

Originally Posted by Interceptor5.0

Symptoms:
-Rough idle but smoothes throughout RPM band.
-valve chattering
-slight oil smoke from from exhaust
-noticable power loss from low RPMs but less as RPMs/speed increases.

The slight oil smoke can be caused by an offroad pipe without cats. My car does it very slightly when I am on the loud pedal. The low RPM power loss could be from cylinder bleed, but I also wouldn't rule out the ignition.

Valve chatter? When? What RPM? While idling?

Quote:

-idle smooths - makes me think it's nothing more than a valve(s) opening/closing correctly --> also makes me think Exhaust valve.

This has got me confused. Is there a rough idle and then it smooths out?

Quote:

Originally Posted by QWKSNKE

Has anyone had the valve covers off and looked at the valvetrain?

That would be a good start. But I'd do a leakdown test (which I'm sure Paul is going to do) in order to identify any problem cylinders. It is quite possible that your valvetrain is just messed up. While you are there, I'd check the cam timing too. It doesn't happen very often but your cams could have jumped time or be improperly timed altogether.

Italian LX · 03-30-2005, 08:16 AM

Quote:

Originally Posted by Sendero

The slight oil smoke can be caused by an offroad pipe without cats. My car does it very slightly when I am on the loud pedal.

That's the understatement of the year... unless you fixed something since the last Dragon Run.

coupe · 03-30-2005, 08:21 AM

Nathan: How can an offroad pipe cause oil to seep by either the valve guides or the rings?

Italian LX · 03-30-2005, 08:31 AM

Quote:

Originally Posted by coupe

Nathan: How can an offroad pipe cause oil to seep by either the valve guides or the rings?

I think he was refering to the fact that the cats no longer trap some of the the oil from the blow-by; not that it actually caused the problem.

Sendero · 03-30-2005, 08:51 AM

Quote:

Originally Posted by Italian LX

I think he was refering to the fact that the cats no longer trap some of the the oil from the blow-by; not that it actually caused the problem.

Thats what I mean.

If you got serious blowby (ie, busted valve stem seals or rings) then it sure won't be a "slight" oiling smoking issue.

Scothew · 03-30-2005, 09:21 AM

Mine smokes some when on it. Lil more than I would expect.. I dont think its a major problem.

Sendero · 03-30-2005, 09:32 AM

Quote:

Originally Posted by Scothew

Mine smokes some when on it. Lil more than I would expect.. I dont think its a major problem.

Yours probably smokes as much as mine. I loose very little oil in a 4 month oil change rotation (less than a 1/8 of a quart). On our 4v's I believe most of the smoke is from being to rich rather than blowby.

Scothew · 03-30-2005, 09:46 AM

I dunno, Matt said it was blowing pretty good on the last dragon run. Guess holding 5500+ rpm in 2nd gear down the straights & through the whole 11mi run isnt good on the seals huh

03-29-2005, 09:48 PM	#1
uvbnhad Friends Join Date: Mar 2005 Location: McCalla Posts: 1,241	Help me think this out. Unfortunately it looks as though Ford is going to screw me over on the issue I've been going through based on the bull shit LL created. Now I have to fix the car and I'm going to let Paul do it but I'd like to get a feel for what I'm facing. Symptoms: -Rough idle but smoothes throughout RPM band. -valve chattering -slight oil smoke from from exhaust -noticable power loss from low RPMs but less as RPMs/speed increases. Noticeable things: -no rod/piston knocking - leads me to think there isn't any "severe" internal damage -idle smooths - makes me think it's nothing more than a valve(s) opening/closing correctly --> also makes me think Exhaust valve. Follow me on this and see if it makes sense. Exhaust valve is not closing opening correctly thus not allowing the cylinder to make the normal power; creating a rough idle as the engine is then off-balance. As the rpms increase, the engine doesn't rely on each individual cylinder as much per se. The collective power of the entire engine is greater than each individual cylinder; i.e., inertia. Any thoughts? Am I flawed in my thinking? Another cause?

03-30-2005, 04:46 AM	#2
QWKSNKE 3v's are slow Join Date: Dec 2004 Location: Here and There Posts: 17,152	Re: Help me think this out. ok I am thinking that if it is a valve situation like you mentioned, that it is going to be rough at all rpms or at least noticable. Has anyone had the valve covers off and looked at the valvetrain? Has the car been put on scanner to check for codes? __________________ 2009 Porsche Carrera S 2008 ///AMG C63.. Eurocharge Tune. RIP 2019 AMG GLC43..wife's 03 F250 SD.. Edge Evo, AFE Stage 1 CAI 08 GT. JBA axle back, FRPP springs, FRPP swaybars.. daughter's 01 Cobra vert... wife's I need a new toy

03-30-2005, 08:21 AM	#5
coupe Super Moderator Join Date: Dec 2004 Posts: 6,313	Re: Help me think this out. Nathan: How can an offroad pipe cause oil to seep by either the valve guides or the rings?

03-30-2005, 09:21 AM	#8
Scothew Censored Jihad Join Date: Dec 2004 Location: B'ham, AL Posts: 4,108	Re: Help me think this out. Mine smokes some when on it. Lil more than I would expect.. I dont think its a major problem. __________________ Theres only one way to get to Carnegie Hall..... .... Practice.

03-30-2005, 09:46 AM	#10
Scothew Censored Jihad Join Date: Dec 2004 Location: B'ham, AL Posts: 4,108	Re: Help me think this out. I dunno, Matt said it was blowing pretty good on the last dragon run. Guess holding 5500+ rpm in 2nd gear down the straights & through the whole 11mi run isnt good on the seals huh __________________ Theres only one way to get to Carnegie Hall..... .... Practice.