(800) 853-2651
SHOP NOW

O/T truck question

5

55 50 Ron

Well-known Member
Was going to post this in the truck forum below, but it says trucks of 1986 or older. Noticed there are a lot of O/T things posted here so will try this.

I have a 1991 Ford F-150 XLT with the big V-8, think it"s a 5.1 L. The coolant tank in the left front area of the engine compartment won"t stay at the required level. I fill it to the right mark and after some driving, that little tank is empty again! No signs of any leaking on garage floor or anywhere around the engine. It starts and runs just fine. Temperature gauge reads good. Doesn"t burn any oil and the oil level on the dip stick is correct.

Any ideas as to where that coolant might be getting lost? I've owned it for about 5 years and it has always done this.
 
It isn"t just normal "addition and subtraction" of coolant to and from the recovery tank as the engine warms up and cools off, is it?

When the engine warms up, coolant expands to a significant degree and overflow bypasses the radiator cap to enter the recovery tank. Then, when the engine cools off, the coolant shrinks and is drawn back out of the tank.

On a vehicle with a flat recovery tank, this might be hardly noticeable, whereas with a tall, narrow tank (as in my wife"s Chrysler T&C) the level in the recovery tank can vary by a couple of inches as the engine warms and cools.

If it"s normal, the level in the recovery tank will be at its highest about fifteen minutes after a warmed engine is shut off, and at its lowest after the vehicle has sat overnight and is completely cooled off.
 
Coolant also flows through the throttle body.I had a F-150 with a 5.8 that had the sealing plug at the throttle body leak.Anti-freeze would run down the throttle blade shaft.

Easy to pull air intake plastic tubes off.As someone else mentioned,water pump weep hole is another possibility.
 
when an engine cools down,there is little or no pressure in the radiator.when the engine is run there is a pressure buildup and a leak may start,if it is a slow leak the coolant can evaporate as fast as it leaks,therefore they can be very hard to find.in the case of the throttle body,if it is leaking into the engine you should see some white smoke out of the tail pipe.the answer i like is to check the little hole on the bottom of the water pump for any wetness at all
 
I dont know,I have a Ford car that does the same thing.I have replaced the water pump,still does it.Cant even find any leaking under it any where.My guess is that its going out the exhaust somehow?
 
It doesn't take much of a leak to lose coolant over time. There are LOTS of places a little can sneak out, and evaporate unseen.

Our Yukon would lose a little coolant all the time, and in COLD weather, "mark it's territory" a little on the garage floor.

Turned out the aluminum-with-an-"O"-ring-inside water pump gaskets were bad. You couldn't even see a track where the coolant would occasionaly run down the front of the engine, and leak on the floor in cold weather.

Replaced them, coolant level stays up.
 
My 95 F-150 with 5.0 engine has been doing that ever since I got it. Sometimes it'll go months and not lose a bit, then sometimes it'll be down about a pint in a couple hundred miles. Haven't ever seen a leak, been doing that for about 170K miles at least.
 
We see this all the time in the shop with these trucks...virtually impossible to find, doesn't impact operating temp or driveability and we've never had one come back as an overheat. We tell our customers to drive it, watch the gauge and watch for leaks and bring it back- usually, they forget and we just top it off when we do their oil changes- no harm, no foul
 
Ill bet it is the intake gasket leaking and sucking a very little bit each time down the intake ports in the back of the engine or even leaking at the intake outside in back of the engine. Mine does the same thing on ford 5.8
 
Borrow a pressure tester and pump it up. See what you see. Auto Zone will let you buy one and bring it back for refund.
 
My 88 F150m does it too. It's got the 4.9 6 cyl. Never any other problems, it just goes dry over time. The radiator always stays up though.

Donovan from Wisconsin
 
You must log in or register to reply here.

Similar threads

R
Question on selling price
Replies
12
Views
410
Leroy
L
O
Oil level rising
Replies
9
Views
437
OregonAaron
O
C
Blown head gasket? 8N
Replies
7
Views
267
Eman85
E
P
CASE 880 Excavator
2
Replies
28
Views
3K
jean claude marleau
J
W
o/t maybe Question of Michigan Firearms Association
Replies
10
Views
523
DoubleO7
DoubleO7
Tractor Parts Tractor Manuals

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Copyright © 1997-2024 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy

Back
Top