Too much engine oil. A problem?

jrh99

Member
Established Member
Joined
Nov 3, 2002
Messages
613
Location
MA
So I just bought a 93 Cobra and when I checked the oil, the level appeared to be a bit high. I've never owned a 5.0 so I had no idea how many quarts they took. Before going to buy the oil and a filter I sent the guy I bought the car from an email and asked how much he was putting in. He said 5 1/2 quarts. My buddy told me they only take 5 quarts and that seems to be the consensus here too. I figured it was due to the V1 S-Trim on the car, but when I spoke with Vortech they said that I shouldn't add any extra oil due to having the supercharger.

The previous owner only put about 1500-2000 miles on it. So assuming he was the only one that was putting a 1/2 quart of extra oil (62,000 miles)... my question and concern is, could this have done any damage?

I've got oil and a filter ready to swap... it just needs to stop raining first! :fm:
 

buddha93

Well-Known Member
Established Member
Joined
Oct 31, 2002
Messages
2,635
Location
St. Louis
Extra oil can hurt an engine, but in your case an extra 1/2 quart is going to kill it. I would however drain that little extra out.
 

bat-stang

The REAL Dark Knight
Established Member
Joined
Feb 12, 2006
Messages
800
Location
H- Town, TX
I've heard of some folks running a QUART high to keep some level in a daily driver on a road course to keep the pump from cavitating during hard cornering. I think the issue is that too much oil can get onto the crank (besides what is being pumped throughout the system) causing a detrimental slowing of the assembly. I don't know personally, but while stuff is spinning, thowing a heavy liquid onto it can have some ill effects.
 
Last edited:

cobr96

getting old
Established Member
Joined
Oct 30, 2002
Messages
994
Location
Texas
A half quart wont hurt , but if a engine has too much oil , the cranshalft can hit it in the pan causing it to foam up, and the oil pump cant pump foam. This is why there are windage trays that are added .
 

jrh99

Member
Established Member
Joined
Nov 3, 2002
Messages
613
Location
MA
One person I spoke with mentioned the extra oil might create extra oil pressure and ruin gaskets (I'm not sure how true this theory is). I don't see any leaks at all and she doesn't burn a bit of oil, so I guess there was probably no harm done. I just figured I'd see what you guys thought since I have been told that running too much oil is worse than running too little.

It finally stopped raining around here, so I'm going to change her now anyway. :)
 

jrh99

Member
Established Member
Joined
Nov 3, 2002
Messages
613
Location
MA
The oil has been changed, but I have another dumb question. It looks as if there are 2 drain plugs. One is towards the back and pointing down. That's the one I drained. The other is below the filter and pointing forward. I didn't drain that one. Should I drain both next time?

Thanks for the head up!
 

Cobra228

Random SVT Poster
Established Member
Joined
Mar 20, 2002
Messages
180
Location
Raleigh, NC
I've had two fox body 5.0's now and the dipstick has never been accuarate on either one. It has always appreared to be overfull if you go by the notches on the stick. If you are going by the dipstick its not going to give you a true measurement.
 

cobr96

getting old
Established Member
Joined
Oct 30, 2002
Messages
994
Location
Texas
the oil pump is what controls the amount of pressure not the amount of oil, unless the oil level is extremely low or out of oil. And yes always drain both plugs otherwise your just leaving dirty oil in there.
 

cobra186

Stang Trader
Established Member
Joined
Oct 19, 2002
Messages
2,038
Location
Tx
By not draining the front sump... you just left about 3/4 quart of oil in the pan. Now you are worse off than the 5 1/2 qts the previous owner was dumping in.
 

670 of 4993

Head Colostomizer
Established Member
Joined
Aug 27, 2006
Messages
688
Location
Connecticut
what they all said ^ lol

but yea, use both drain plugs...one issue i have is the ammount of oil after i installed my blower...only takes 4 quarts. I'm guessing that because the blower is holding some
 

sm1993svtblk

Member
Established Member
Joined
Oct 20, 2005
Messages
223
Location
Topeka, Ks.
By not draining the front sump... you just left about 3/4 quart of oil in the pan. Now you are worse off than the 5 1/2 qts the previous owner was dumping in.
Damn people, your cobras hold 5 qts whether it has a blower or not. Always drain both the front and rear drain plugs.
 

jrh99

Member
Established Member
Joined
Nov 3, 2002
Messages
613
Location
MA
By not draining the front sump... you just left about 3/4 quart of oil in the pan. Now you are worse off than the 5 1/2 qts the previous owner was dumping in.

In that case, the previous owner must have had around 6 quarts in the engine, because I'm still lower on the dip stick than he was by quite a bit. I'll definitely drain both plugs next time and I'll drain a bit from what is in there currently.
 

jrh99

Member
Established Member
Joined
Nov 3, 2002
Messages
613
Location
MA
Damn people, your cobras hold 5 qts whether it has a blower or not. Always drain both the front and rear drain plugs.

Yup, I spoke w/ Vortech, they confirmed this. The Vortech guy said the oil just sprays over the internals and then just drains right out... I guess nothing ever pools up inside anywhere.
 

comprepsvo

Active Member
Established Member
Joined
Oct 5, 2004
Messages
316
Location
Ringgold,Georgia
I thought the biggest concern with too much oil, was that the pistons on the downstroke could be in contact with the oil level in the crank and there fore hit the level of the oil which is somewhat non-compressible and therefore cause too much stress on the crank side of the piston. Am I wrong?
 

kcp203

Member
Established Member
Joined
Feb 25, 2003
Messages
159
Location
New Jersey
I've had two fox body 5.0's now and the dipstick has never been accuarate on either one. It has always appreared to be overfull if you go by the notches on the stick. If you are going by the dipstick its not going to give you a true measurement.

Ditto. None of my 5.0's have had accurate dipsticks. Drain both sumps, and add 5 quarts with a new filter. You can then re-mark your dipstick with the new fill line to measure from in the future.

P.S. no wonder people question domestic auto quality when they can't even get something as simple as a dipstick right.
 

red95gts

New Member
Established Member
Joined
Jul 1, 2007
Messages
324
Location
Edmond, OK
I thought the biggest concern with too much oil, was that the pistons on the downstroke could be in contact with the oil level in the crank and there fore hit the level of the oil which is somewhat non-compressible and therefore cause too much stress on the crank side of the piston. Am I wrong?


It would have to be waaaaaaay overfilled with oil for that to happen. I'd imagine you'd run into other issues before this would happen.

I was stationed with a guy who had a late 80s Pontiac Sunbird with a small 4-cyl in it. He added some oil one day before making a ~300-mile trip from his parents house back to base. He gets to work the next day and mentions that the car is making a funny noise. After asking several questions, I determined that he added oil into the valve cover until it "looked full". I suggested he bring it to the base hobby shop and I helped him drain the oil.

We overflowed a 12 quart oil drain pan and mopped up probably another 2 qts off the floor... :eek: How it made the 300 mile trip with 10 EXTRA quarts of oil is just beyond me. Needless to say, the car never really ran right again.. :)
 

1BAD93SVT

New Member
Established Member
Joined
Jun 17, 2004
Messages
1,842
Location
California
adding to much oil while most likely cause white smoke to come out of the exhaust. i usually just drain the rear sump. never had an issue.
 

bat-stang

The REAL Dark Knight
Established Member
Joined
Feb 12, 2006
Messages
800
Location
H- Town, TX
I usually run a quart high--about 6 quarts. Now, my car uses about a quart every two months, so I got to stay ahead of the game. My car sees about 20k a year.
 

Users who are viewing this thread



Top