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Topic: 3.8L shakes (Read 1059 times) previous topic - next topic

3.8L shakes

I have 1988 cougar 3.8L it shakes at idle in Drive or when your driving when it hits top gear???? so any info would be helpful

1978 Ford Thunderbird Town Landau.
351 mod... not for long :beatyoass:

3.8L shakes

Reply #1 –
motor mount?
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***** Project "EVOLUTION" 1987 Cougar LS  & 1985 Cougar Convertible *****
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5.0 HO 306 roller block, machined GT-40P heads, Wiseco dished forged pistons, Eagle forged floating I-beam connecting rods, Lunati pushrods, ARP bolts, Scorpion aluminum 1.6 rockers, Comp Cams Magnum 266HR, Explorer intake, 65mm TB, MAF Conversion, 19# injectors, Ford Racing stainless P-headers, 2-1/2" cat-less exhaust w/ Flowtech Afterburner lers , SC AOD with 2800 BDR torque converter, 3.73 T-Lok rear, CHE rear control arms, full 2-1/2" frame w/1" jacking rails & seat supports, Rear disk brakes, Turbine wheels, All original interior w/ floor shift upgrade .......
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3.8L shakes

Reply #2 –
i was thinkin the same thing. then again geordon.... it could be somthing stupid oh say like a vacspoogee line undone near the map sensor?

Ill have to take a look at it when you bring it to school bro.

3.8L shakes

Reply #3 –
When I had my first Bird,a 3.8 car it shook as well.Motor mount was bad.New rubber biscuit,all good.About a year later,same problem,bad head gasket.bad enough that the engine was shaky,but not bad enough that it was noticeable right off.
'88 Sport--T-5,MGW shifter,Trick Flow R intake,Ed Curtis cam,Trick Flow heads,Scorpion rockers,75mm Accufab t-body,3G,mini starter,Taurus fan,BBK long tube headers,O/R H-Pipe, Flowamaster Super 44's, deep and deeper Cobra R wheels, Mass Air and 24's,8.8 with 3.73's,140 mph speedo,Mach 1 chin spoiler,SN-95 springs,CHE control arms,aluminum drive shaft and a lot more..

3.8L shakes

Reply #4 –
bad Harmonic balancer ?
Never drive faster than your guardian angel can fly.
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1983 base model,1969 302 (originally a v6),upraded c5,currently 30,441 original miles.

3.8L shakes

Reply #5 –
Can you spin your harmonic balancer without turning the enigne?  SC 3.8s suffer from chronic bad balancers.

I would start with the common stuff.  Vac Leaks.

Is it missing?  If the engine will idle, do a KOER and a goose test to do an engine balance test.  The CEL will then blink the low power cyl.  Check the plug, wire, gap in the cap. 

If it runs a like a bat out of hell at WOT but stumbles and chokes at idle and part throttle, its most likely a vac problem.

3.8L shakes

Reply #6 –
my engine shakes when i gas it. also when i do the R to 2 test. ive noticed the driver side mount lifts right up, cant tell for the pass. side but its safe to assume thats shot too.

never thought to check the harmonic balancer but ill do that when i get a free moment to.
"Beating the hell out of other peoples cars since 1999"
1983 Ford Thunderbird Heritage
1984 Ford Mustang GT Turbo Convertible

3.8L shakes

Reply #7 –
Tough call without seeing it.  My guess, if its also performing badly (brrr vrrrooo...bbrrrr...vrrooooo...brrr....vrroooooo during acceleration) as it picks up speed then its engine/fuel/spark related.

If it still performs as it did when it didn't shake (smooth acceleration) then its something else.

When the supercoupe dampeners go bad, you can usually see a wobble on the pulley.
 

3.8L shakes

Reply #8 –
theres really no guessing at all to this.  A vac line undone will 9 times out of 10 cause a high idle situation.

so....
start off with a step by step.



Do you have nice ***BLUE*** spark at each spark plug?

Do you have 40 PSI Fuel presure at idle and 35+ while reving?

does your engine rpm jump up when you spray carb cleaner along various vac lines and also along the intake?

Is your PCV system gummed up with sludge?

motor mount defective (your looking into that)

What codes do you get?

What color is your exhaust?

Does your Catalytic glow orange (inspect at night when hot at idle)

When were your TFI and Hull Effect last replaced?

Does your TPS read properly?

What recent work has been done to the car by you or anyone else?

What are your codes?

Can you remove the Air charge temp sensor and spray it clean of any build up and still have the same problem?

what are your codes?

and last but not least,, what are your codes?

finally,
what codes do you have?



More information is better than too little.  CHeck out my DIY link for other information about the 3.8 and other things you will need to troubleshoot.  Since it shakes during the whole shift cycle of the tranny, it sounds more like a spark related issue and you need to clean out the dizzy for debris on the magnetic pickup and /or verify fuel presure.