How To Find & Fix Coolant Leak

[sludgegine]

既然coolant leak是如此的常见,又如此的害人不浅,特立此主题.

正好找到一个资料,就算是抛砖引玉吧.

http://www.aa1car.com/library/coolant_leaks.htm

以下先重点研究front(timing) cover gasket leak.其它leak先放在一边.

[sludgegine]

Revised October 2005
Page 1 of 1
Technical Service Bulletin 89-1R2
Coolant Leaks into Engine Oil
Any internal leakage of coolant into the lubricating oil in an engine can cause
serious damage to the engine. Some examples of areas where coolant could
enter the oil are:
1. Damaged head gasket
2. Cracked head
3. Cracked block
4. Leaking oil cooler
5. Leaking cylinder inner seals
6. Leaking injector seals
Coolant causes the lube oil to change chemically as indicated by the milky
appearance of the oil. Coolant contaminated oil does not provide the high
lubricity required between close tolerance parts, thus causing friction heat. The
heat causes more oil deterioration. Sludge begins to form, interfering with:
1. Positive operation of lubrication system pressure regulator
valves and the oil filter by-pass valve.
2. Oil filtration suffers as filter material becomes plugged. The
filter may even experience such high
pressure differential that interior parts may collapse.
This contaminated lube oil does not properly lubricate bearings. The first effect is
excessive wear to internal engine parts. The oil does not provide the film strength
needed between the rod and main bearings and the crankcase journals. High
temperature friction melts and welds the bearing surfaces to the journals.
Check the coolant level regularly. Also, check the coolant recovery tank level.
With a cold engine, the fluid level should be at the "COLD LEVEL" mark. If
additional fluid is repeatedly needed to maintain the proper coolant level, then a
coolant leak is likely. It must be determined whether this is an internal leak or an
external leak. Corrective action should be taken immediately, especially if there is
an internal leak.
http://www.filtercouncil.org/techdata/tsbs/89-1R2.pdf

[sludgegine]

这有一段内容是专门针对front cover gasket leak的.

If the water pump cover or the engine front cover is warped from previous overtorqueing or something it is possible to have a coolant leak in that area.

First thing is to make sure you have the proper 6 pellets of the GM coolant supplement/sealer in the system. It is excellent for sealing seeps at gaskets and such.

The OEM gasket is specifically designed for that sealing application. If you have a persistent leak and used an aftermarket gasket/aftermarket pump you might consider the OEM parts and replace the gasket/pump.

Remove the pump and reassemble using a thin layer of RTV on the gasket in the vacinity of the leak point. Key here is to make sure the parts are squeeky clean, use a new gasket and LET THE RTV CURE FOR 24 HOURS BEFORE FILLING WITH COOLANT. The reason RTV gets such a bad reputation is that people put it in a joint and fill the system and expect it to seal....it must cure first. And, in the application of a pressurized joint like the cooling system it needs to cure to full strength before use or it will just be blown out. The RTV can be used to repair a heavily warped surface if it is allowed to cure properly before use.

BTW...the most common reason I have seen for the 4.1/4.5/4.9 water pump cover leaks is overtightening of the fasteners causing deformation of the water pump cover and the engine front cover.


http://www.cadillacforums.com/forums...ing-cover.html

[sludgegine]

看看这位diyer是怎么修timing cover gasket leak的.(有图).

http://www.fordf150.net/forums/viewtopic.php?t=58104

[sludgegine]

这个贴里虽然没有给出solution,但对于Timing cover gasket及周边的结构有比较深入的描述.

http://www.thedieselstop.com/forums/...t-leak-183857/

[sludgegine]

http://www.automotivehelper.com/topic493669.htm

Windstar timing cover leak?


randywirtzfeld
12-13-2005, 10:19 AM
I have a 96 Windstar 3.8L, there is a external coolant leak after you take it out on the interstate and run it hard. It looks like its coming from the timing chain cover? Does the timing chain cover seal any coolant passages? Its not coming from the water pump, but further in, between the timing chain cover and the block? Unless I'm missing a leak up top and its running down to this area, but I don't think so.

I see my repair manual recommends teflon sealant on one bolt that goes through both the water pump and timing chain cover. If the threads were not sealed anymore wouldn't the coolant follow the bolt up to the bolt head and leak there?

Thanks,

Randy
DRW1000
12-13-2005, 11:35 AM
I certainly do not know for sure but I think I remember someone mentioning that they replaced the water pump and did not put sealant on one particular bolt and then they had to remove it and add the sealant because of leaking.

You may be onto something
Winny_the_Pooh
12-13-2005, 02:55 PM
Randy,
I sympathize with you as I also have a '96 with a 3.8L and , also, I do not have good news for you. There are actually 2 coolant passages through the timing chain cover to the block from the water pump. Unfortunately, this engine has a history of leaks in this area, presumably from the gasket itself. There are also 5 stud bolts that go through the water pump and timing cover to the block, one of which goes into the water jacket on the block.

If the gasket has failed, you will probably also leak coolant into the oil pan. If you drain the oil and the first fluid out looks reddish brown, you probably have coolant in the oil.

I took on this repair myself about a year ago. It is do-able for someone who is reasonably handy but, in my opinion, was even more involved than the head and lower intake gasket repair (which I did two years ago). So, unfortunately, I speak from first hand experience.

Good luck and let us know if you have any other questions.

George

L
wiswind
12-13-2005, 05:24 PM
I was quoted $1200 by my dealer to replace the timing cover gasket. They said that the part is cheap.....so it was most all labor.
I had a seapage at that location...and....I believe at the lower intake gasket. As the leak was a seapage.....I added some Bar's "Stop Leak" to the radiator. I prefer the "Liquid Alluminum" or the other kind that is similar. I did use the "pelletized" type once.....but found it hard to add as the transmission cooler is right under the radiator cap...which made adding the pelletized form difficult.

I change my coolant each year.....and keep the correct dosage of the Bar's Stop Leak in the coolant at all times. Has kept the leak under control for several years.

The first time that I changed the coolant......and did not add the stop leak product.....I developed the slight leakage again....after about 6 months.

I changed my thermostat this past summer.....and it....and everything around it was spotless clean....no deposits of any kind.

I would recommend sticking with one of the products under the Bar's brand.
randywirtzfeld
12-14-2005, 06:16 PM
[QUOTE=Winny_the_Pooh]Randy,

I sympathize with you as I also have a '96 with a 3.8L and , also, I do not have good news for you. There are actually 2 coolant passages through the timing chain cover to the block from the water pump. Unfortunately, this engine has a history of leaks in this area, presumably from the gasket itself. There are also 5 stud bolts that go through the water pump and timing cover to the block, one of which goes into the water jacket on the block.

If the gasket has failed, you will probably also leak coolant into the oil pan. If you drain the oil and the first fluid out looks reddish brown, you probably have coolant in the oil.

I took on this repair myself about a year ago. It is do-able for someone who is reasonably handy but, in my opinion, was even more involved than the head and lower intake gasket repair (which I did two years ago). So, unfortunately, I speak from first hand experience.

Good luck and let us know if you have any other questions.

George


Thanks for the reply. I also did the head gasket repair about 3000 miles ago. Sounds like I will have to bite the bullet and repair this now. What's the laundry list for this repair?

Water pump
water pump gasket
timing cover gasket
crankshaft seal
oil pan gasket(I assume this needs to be removed?)

Anything else?

Thanks,

Randy
wiswind
12-14-2005, 06:51 PM
According the the instructions that I read....you need to drop the oil pan...which requires dropping the "Y" pipe....which is the one piece unit that contains the 2 catalytic converters.....and pipes to the exhaust manifold, and up to the flex pipe that is right in front of the big square muffler.
Instructions tell you to be careful not to miss the bolt that is hidden behind the oil pump.
Check out the instructions at www.autozone.com
They say to remove the engine from the car.....several people have posted that they did the job without doing that.....but you DO have to raise the engine up a few inches to be able to clear the frame member with the water pump pulley.

It looks like you have to mess with the pulleys on the front of the engine....and the oil pump......

Also...from what I read....the new FORD gaskets are improved....so as to not fall apart.....like the original ones did.

My leakage was not bad enough to even make any drops under the car....so I was lucky.

If you have a digital camera......could you take pics and post them?.....this is a VERY common failure...and I know that many people would be helped greatly by pictures and instructions from your experience. I may be one of them in the future if the leaks come back.
Winny_the_Pooh
12-14-2005, 10:10 PM
Randy,
I went back over my notes and here is the material I purchased

1) Timing Cover Gasket Set. I used Felpro P/N TCS45951 and it included:
a) timing cover gasket
b) water pump gasket
c) oil pump gasket
d) crankshaft front seal
e) the larger o-ring in the water pump inlet to seal the lower tube to the radiator ( I believe. There is also a smaller o-ring on an upper tube into the wtop of the water pump. Between the timing cover kit and the water pump, I got both of the o-rings I needed).
f) RTV

2) Oil pan gasket set. Felpro set includes:
a) rubber gasket for rear main seal
b) lotsa RTV for the rest of the gasket

3) New water pump (includes gasket, so now you have two)

4) Timing chain and timing gears (judgement call - I figured why not since I had it apart).

5) coolant

6) Teflon thread sealant

7) vibration damper puller (rented)

8) power steering pulley puller (rented)

9) New stud bolts from Ford (judgement call)

10) New gasket for exhaust pipe (depends on where you decide to unbolt the back end of the exhaust)

11) Maybe consider a new belt if it's been awhile.

12) anti-sieze compound (for exhaust bolts)

13) petroleum jelly (to repack oil pump)

14) I find a Haynes, Chilton, or Ford shop service manual helpful.

15) it's nice to have a parts washer. I use a cleaner called Hurri-safe in mine. Bought it over the web.

Wiswind is correct, you have to lower the exhaust to get at the oil pan conveniently (and you are correct, you have to lower the oil pan to free the bottom of the timing cover). You can do the job in the car but you do have to remove the nuts to the two motor mounts on the passenger side (front and back) and jack up the engine to get the water pump and pulley to clear the wheel well. I had the car up on three jack stands and removed the passenger side wheel to help with access to that side of the engine.

You will also have to remove the CMP to get the cover off. As you probably know, the CMP timing is critical. I set my engine to TDC on #1 and never let it move until the CMP was back in. Plus, I made careful notes on the position of the CMP vane (with the cover off) and the position of the CMP body ( the body where the hold-down washer is positioned will be clean and gives you a reference when you are re-installing it).

If you decide to tackle the job, I have more thoughts on things to watch for. This reply is a little verbose so I will cut it short for now. But, please let me know if you would like to hear more.

George
randywirtzfeld
02-13-2006, 11:20 AM
George,

I am going to take on this repair tommorrow. You mentioned you may have a few more tips for this repair, fire away, I could break a rubber ball, in a rubber room.

Thanks for the initial reply also,

Randy
LeSabre97mint
02-13-2006, 12:48 PM
George,

I am going to take on this repair tommorrow. You mentioned you may have a few more tips for this repair, fire away, I could break a rubber ball, in a rubber room.

Thanks for the initial reply also,

Randy

Randy

While you have your crossover pipe off you may consider replacing your Vehical Speed Sensor (VSS). This part isn't very expensive, but when it goes bad the trannie doesn't know when to shift,......the cruse doesn't work

It's in a tough place to get at and dropping the Y pipe is helpful.

MHO


Dan
randywirtzfeld
02-14-2006, 06:04 PM
I started this job and already realize I made a mistake. How do you correctly reposition the camshaft position sensor? I marked the base on the outside by the hold down bolt but I neglected the taking the cover off the top and marking the placement of the vane that turns inside the top. My repair manual makes reference to an alignment tool for this purpose, but where would I get one, every time I go to a dealership for a specialty tool they give my the cold shoulder. I doubt any of the places like Checker or Napa would have one? Or could someone describe how the vane should be positioned with the Number #1 cylinder at TDC?

Randy
12Ounce
02-14-2006, 09:27 PM
Randy,

Those tools are available from SPX- OTC tools.
http://www.otctools.com/frames-catalog2.php3
Look under "engine service" ... I think the part number for your engine is 6469.

Another method is find a friend with your year model Windstar with a 3.8 ... move the crank until cyl #1 is at TDC. Pull off the cam pos sensor and have a look.
randywirtzfeld
02-15-2006, 11:01 AM
I bit the bullet and bought the tool off ebay. Thanks.
Winny_the_Pooh
02-19-2006, 11:30 PM
Randy,
If you have the engine set at #1 TDC, then the vane will be on the right hand side (with you standing at the front bumper and looking back to the rear of the engine/firewall). The vane turns CCW so the "leading edge" will just be entering the notch/cutout in the rear of the housing and the "trailing" edge will just be about to enter the front notch in the housing. If you then clamp the hold-down washer on the same place of the CMP housing (based on your mark or, in my case, the clean/dirty areas), you should be very close.

As you lower the CMP into the timing cover, it will have a tendency to spin slightly as the gears engage. So, you may have to preset the van a litte bit earlier than the desired final position so that it spins right into where you want it.

I used this verbal description from a poster on Cartrackers.com by the name of Wrestler and I was able to get the CMP positioned correctly. If you are close, the worst that may happen is that the engine may hesitate slightly on acceleration. If so, you can slightly adjust the housing until this goes away.

I hope this helps.

BTW - How far along are you? DO you already have the cover back on?
Winny_the_Pooh
02-20-2006, 08:47 AM
Randy,
I sent you a powerpoint slide and a picture of my CMP position in seperate e-mails. The second e-mail had a little problem getting out initially but I think I got it to go. Please confirm if you did not receive these two e-mails and I will resend.

George
PS - If anyone is willing to post these on the web somewhere for the masses to use, please e-mail me and I will forward them to you.
jakethebt
12-11-2006, 10:05 PM
Any updates to this or new tips? It looks like my gasket gave up the ghost. I will try and put it off with some stop leak... but it sounds like I will be changing the gasket too.

Question... when you jack up the engine in the van after loosening up the mount bolts, can you get it high enough with the transmission and axle shafts still in place?
alofile
12-11-2006, 11:23 PM
Yes, you can jack up the engine so you have enough room to remove the water pump than the front cover.
Winny_the_Pooh
12-12-2006, 02:14 PM
Alofile is correct - you do have enough room. You may have to hold your jaw just right to get everything to clear but it can be done.

LeSabremint97 gave a good tip - change the VSS while you have the exhaust off. I did not and I had to drop the exhaust again when I my VSS went out and threw a CEL with a P0500 code. It sucked dropping the exhaust the first time so it wasn't fun dropping it again (but you get a good bench press workout). The bolts on the yoke tend to splay out and it is a bear to get them to re-align with the holes in the "yoke" on the flared end of the y-pipe. I had to find a stiff pipe to use to bend them back straight enough to get the yoke back on.

Keep track of which studs go into which holes on the cover and water pump. I seem to remember that some are different lengths or different thread lengths. You can "double nut" the ones that are giving you trouble in breaking the initial torque.

The Ford manual is not really clear on which stud needs the thread sealant to keep from leaking. So, I sealed a couple of them on the firewall side to be safe (this was after one of them started leaking on me - another do-over task).

I also had to do-over the gasket to the water pump. It started leaking so I had to use RTV the second time in addition to the gasket. It was a good thing I got two gaskets in the material list I provided earlier.

I have info on the CMP position that I am trying to get posted to the web.
alofile
12-12-2006, 05:24 PM
What gasket you are going to use. If you use the Felpro. Make sure you have the blue colour with rubber material. not the paper. They use the same part no. But I can tell you the harder part is how to take out the front cover when all of nut & bolt removed. I broke my cover when I took it out. Good luck.
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