• Hello there guest and welcome to our forum!
    To gain full access you must Register. Registration is free and it takes only a few moments to complete.
    Already a member? Login here then!

something is wrong with my 5.0

gearjammer5.0

Well-Known Member
hey guys i need some help figuring out what is wrong with my 1989 mustang gt 5.0 5-speed, i was racing at qualcom winding out to 6k no problem, but then on my tenth run i all of a sudden started loosing power after 4k, it was a slow power killer and i had the pedal to the metal, so iam asking you guys what you think it might be. oh yea i changed my oil before the race, full synthetic 10/30, and now i have lower oil pressure what should i do?

thankz guys!!
 
M

Mustangcwo

Guest
You need to pull each every spark plug and see if they all look the same. Let us know what you find and we'll go from there. Low oil pressure could be caused by many things. Did it overheat? Did you hear any strange noises?

Also need to know if it threw any codes??
 

wickedstangs

Chula Vista, CA
Staff member
Administrator
gear what exactly is happening at 4K? Is the power just stoping? Cutting out? How do you know your losing power?

Now about your oil pressure what do you mean lower? What was it at in the begining? and what is it at now?
 

blackstallion06

Everrett Wa. Soon to be St. Louis MO.
Donator
I would check the fluids. Maybe your head gasket is going or something. liek the guys said what are the exact problems
 

gearjammer5.0

Well-Known Member
this is jammer - when i mean i am losing power after 4k, i mean gradually, it doesnt just shut off, and before i ran synthetic i had 60 to 70 oil pressure, now only around 40 to 50, and i changed my spark plugs, coil, and wires, before i raced it, so i dont think its electrical. now my tempature gauge dosent work, so i dont know if i was overheating, and yes i did hear a strange noise, it sounded like an exhaust leak but only when i am in gear, and the more rpms i had the louder and faster the noise got, but if i rev the car with the clutch in or in neutral, the car doesnt make that noise.
another wierd thing is that i have been just driving around town, i will tac it out to 6k and no loss of power, but i do still hear that hissing sound. maybe i was overheating? i honestly dont know what is wrong? please help me you guys.
 

gearjammer5.0

Well-Known Member
this is jammer - when i mean i am losing power after 4k, i mean gradually, it doesnt just shut off, and before i ran synthetic i had 60 to 70 oil pressure, now only around 40 to 50, and i changed my spark plugs, coil, and wires, before i raced it, so i dont think its electrical. now my tempature gauge dosent work, so i dont know if i was overheating, and yes i did hear a strange noise, it sounded like an exhaust leak but only when i am in gear, and the more rpms i had the louder and faster the noise got, but if i rev the car with the clutch in or in neutral, the car doesnt make that noise.
another wierd thing is that i have been just driving around town, i will tac it out to 6k and no loss of power, but i do still hear that hissing sound. maybe i was overheating? i honestly dont know what is wrong? please help me you guys.
 
M

Mustangcwo

Guest
You need to bring your car to one of us and let us check it out.

When you say you tach it out to 6K, is that on purpose or is the engine taking off on you?
 

beejay31000

BULLWINKLE
Oil pressure will drop with synthetic, thats normal, but 50psi is still okay. Sounds like the only usse you are having is when there is a load on the engine....which makes me think of detonation.
 

gearjammer5.0

Well-Known Member
my car is missing when its idleing, i dont know what it is? i already installed a new cap, rotor, coil, wires, i changed the spark plugs to but it is still missing, and smells like gas, seems like its running rich but i dont know why? and i feel a loss of power, it used to be faster.
 

beejay31000

BULLWINKLE
whats the timing at?? is it throwing a check engine light?? its def engine....not tranny. maybe a sensor broke or its tuned wrong. probably something kinda small.
 
M

Mustangcwo

Guest
You need to put it on a code reader and tell us the list of codes. Could be many different sensors or just one. You could be chasing it for awhile.
 

510z

Well-Known Member
i agree pull the codes to start, you dont have to buy a code reader, all you need is a paper clip and your CEL.

also check the basics, pull the plugs and check them out, check for fuel or oil soaked plugs etc etc, do a compression check and post your numbers, check ignition timing and fuel pressure, check and clean you MAF.
 

GLDNPNY

Well-Known Member
Give me a call. I have a good OBD I code reader. Bought it for my L and the 90. If you want to meet up we can see if there are any codes. Are you seeing any "new" tailpipe emissions? You say you hear a noise under load. Is it metallic? Have you done a leakdown or compression test? Maybe pull the valve covers and see if you may have tap danced on the limiter (factory 6250) and maybe backed off a few rocker arms. If you have stock valve springs the runs to 6K may have fatigued them. Although I don't see stock valve springs getting you to 6K in the first place. Someone earlier mentioned a possible head gasket. Are you seeing bubbles in your coolant? Is your coolant a milkshake? Are you LOOSING coolant? There are a myriad of possibilities but if it is throwing a CEL we could start there. EEC IV computers tend to be hypochondriacs. They will cry about anything. Some codes are BS. Some are legitimate.

Eric
6189808530
 

beejay31000

BULLWINKLE
you have an MSD ignition? ive heard of them going bad....that could be it.....who knows. like everyone says, chech the codes
 

gearjammer5.0

Well-Known Member
no iam thinking of buying one to see if it would help me burn my fuel better, because i can smell alot unburnt gas. should i buy a msd 6a box or not?
please answer.
 

IgottaV8

Wickedstangs Road Racing Team
Staff member
Moderator
Board Member
I don't have an msd 6a ignition, and my car runs fine, I have heard the same thing about their distributors though. Don't knowhow founded it is because I've had the same MSD distibutor since before I bought the car and I've had no problems.
 
Top