Ford Mustang Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter #1
Hey guys, I'm New here so I'll try to keep this simple and maybe get some help. I'm no mechanic by far but growing up, I was a "daddy's girl" so I learned a few things about engines and how they somewhat work. Any way, a few weeks back I traded my Chevy Avalanche 5.3 V8 for a 35th anniversary edition 99 mustang 3.8l V6 w/ 121504 miles on it cause I was thinking with gas prices being as they are, surely i'd do better with a smaller engine and gas tank. Was told it had a new clutch, pressure plates and throw out bearing and shifted good except for the squeal that what stop if i applyed slight pressure to the clutch. Ran great for about 4 days or so and I realized after filling my tank up, I only had 1/4th left and only driven167 miles. Then I noticed white smoke whenever i'd crank the car and black if I reved it up so i changed my air filter, checked the coolant and oil, which I had to add 2 quarts of and let it sit over night to cool so i could repeat the process in the morning. Same thing except this time my service engine light came on and would start flashing while I was driving. Took it by O'Reilly's to have tested and it read misfire on 1&3 so i bought plugs and wires and changed them, which was not fun by the way, cranked right up and still smoke but light was off. Next day, same thing, light on, white smoke. Took PCV off, cleaned it. Took EGR off, cleaned it, glad I did, it was bad clogged. Sanded it down and painted, yes I painted it. Lol (Rustolium High Heat Black) at this point I may have 200 miles on it and have had to add $10 in gas. so again, light off drive a little bit, car starts loosing horse power, light back on so back to O'REILLY's I go. Misfiring1&3 again so this time I put a coil pack, check my firing order to make sure the wires are in the correct position, cranks a little better but still loosing horsepower, spitting and sputtering, can't run AC so i call the car lot and they send me to their mechanic who basically tells me I've done all I can, stop wasting my money, I need a rebuild or engine replacement. Sorry for the long introduction but can somebody steer me in the right direction? Oh and cats are good, no exhaust leaks although to me it seems to be running hot inside and out even though temp gauge says A-ok. Could this possibly be cylinder damage? Thanks
 

·
Super Moderator
Joined
·
39,947 Posts
Welcome to the site!! I moved your thread for a better response.
 

·
Registered
Joined
·
252 Posts
White smoke is possibly head gasket problem and you need to do compression test.
Good news is 3.8 is a pushrod engine and much easier to work on comparing to 05 Mustang 4.0 OHC engine, designed by morons(engine has to be removed for head gasket replacement)
 

·
Registered
Joined
·
946 Posts
I'd say a bad head gasket also, but if compression checks out, intake gasket can cause similar issues if it's bad enough. To check for compression, rent a cocompression tester or borrow one, remove a spark plug (I'd check the mis fires first) and crank by hand to see if it's creating proper pressure. If it's too low you know the head gasket is bad.

Sent from AutoGuide.com Free App
 

·
Registered
Joined
·
252 Posts
Before test:
remove fuel pump relay or fuse while engine is running, it will stall in a few seconds
disconnect connector from ignition coil
 

·
Registered
Joined
·
1 Posts
The 3.8L engine is notorious for intake gasket leaks. Since you have 120k miles on the engine, I would strongly suggest changing both the upper and lower intake gasket.

Here is the problem, the gasket is made of plastic which weakens with heat and time. When it starts to fail, it will leak coolant into the combustion chamber. (This will cause white smoke as you described and loss of coolant) Over time, it will cause catastrophic damage like head gasket failure, cylinder head warp, or even cracking.

This is what you should do to determine what problem you have.

1. Complete a compression test on all six cylinders. (You will have to find a service manual to get the acceptable values, but off the top of my head something between 160 and 200 PSI should be fine.)
If you have a huge (low) variation in a cylinder, fill the cylinder with approximately one teaspoon of oil and test again. If the compression doesnt come up, you most likely have a warped or cracked head at that cylinder. (That's bad news)

2. If your compression test is fine, you have a leaking intake gasket. (Not great news, but much easier to fix)

For number 2 above, you will need to replace both the top and bottom intake gasket(s). To do this, you will need a disconnect tool Like this:
Lisle 39440 - 5/8" Angled Disconnect Tool | O'Reilly Auto Parts
So you can remove your fuel rail.

The rest of the tools are pretty straight forward.

Lastly, if it is merely a gasket issue (keeping my fingers crossed for you!), remember to fill your radiator properly when you are completed. The 3.8l is a little finicky and if you have air in the coolant system, it will not cool properly.
 
1 - 11 of 11 Posts
Top