Coolant Loss - Page 3

ShadowLvr400 · #31 (**permalink**) 11-09-03, 10:47 PM

But then why did it leak all my coolant out as soon as I took the cap off?

DaveSmed · #32 (**permalink**) 11-09-03, 11:51 PM

Maybe I missed something, how long did you let the car cool? If it still had pressure in the system from being warmed up it would have forced the coolant out and all over it's surroundings. Try this, while the car is cold before you go anywhere for the day, remove the cap to verify no pressure in the system. Put the cap back on and start the car letting it run for one minute. Shut it off and remove the cap again. There should be no pressure as the coolant has not heated up and expanded yet. If there is pressure, it is unfortunately coming from the combustion chamber.

elwesso · #33 (**permalink**) 11-09-03, 11:57 PM

This guy is all over it!!!! Great info!

ShadowLvr400 · #34 (**permalink**) 11-10-03, 09:25 AM

Dave, the car got to cool overnight. I didn't actually get around to opening it the following afternoon. And as I said, why would the release of pressure cause all the coolant to drain out? And not from that release hose I found before. What kind of pressure regulators/valves etc are there in the coolant system?
Add to that, something squeeks really badly when I start the car. It's on the passenger side, where those belts and pulleys are. Could it be a water pump?

elwesso · #35 (**permalink**) 11-10-03, 10:08 AM

It MIGHT be the water pump.... Obviously something is leaking on the belts causing them to squeak, and after a few seconds it goes away......

Ther really arent any regulators or anything.... About all there is, is the water pump, the radiator cap and the Tstat...... Everything else is just a bunch of passages.......

Now, why would the release cause it to spill?? Im not sure, sorry......

zonie77 · #36 (**permalink**) 11-10-03, 01:45 PM

The thermostat controls the pressure in the cooling system. It may be marked on the cap, 15lbs or 22 lbs, something like that.
Bad headgaskets generally seal when the engine cools and the cap retains some pressure. Remember, there is a huge difference in pressure between running and sitting still but hot.
When you take the cap off the pressure left in the system can blow some antifreeze out.
You will not get water in the oil until the head gaskets are totally blown, the cooling system encircles the cylinder more than on older design engines.

Either have a compression or leakdown test done or do it yourself. That should determine if you have a blown headgasket or not, You can buy the tools to do a compression test for less than having it done.

You'll need a compression tester with a screw in hose(because the spark plugs are recessed into the head) and a sparkplug socket, 3/8drive ratchet, and extension (about 6"). It makes sense to buy a set that has all of this.

Pull all the plugs(on some engines the coil pack is in the way on the back but it only takes 3 small bolts to take off), install the tester in a spark plug hole and crank the engine. Watch the first compression stroke and record that. The compression will creep up as you keep cranking so the first stroke is more definitive for diagnosing. Do all 8 cylinders. If one or more have low compression the head gasket is leaking. (It could be a valve, head, or piston problem but then it wouldn't be running well)

A leakdown test is even better because it can pinpoint the leak better but you need a tester and air compressor so it costs more. I think from your symptoms the compression test is sufficient.

zonie77 · #37 (**permalink**) 11-10-03, 01:50 PM

If we have a section for tech pictures I could put some up os a bad head gasket and the top of the block showing the coolant passages.

ShadowLvr400 · #38 (**permalink**) 11-10-03, 05:34 PM

Zonie, it's the inconsitency of the leak. It'll leak sometimes when the motor's warm and running hard, but will hold it under normal driving. Then it held under hard driving, and normal driving, and held it when sitting idling. Then when the motor was cold, and the cap removed, it finally leaked it all out. Then it continued to leak it out as I refilled, then it held the water again. The car won't hardly do the same thing in the same situation. But, I am probably going to ask my buddy if he'll let me borrow the gear for a compression test from work. I can't afford to take it to a shop though. So, I will learn this motor more and more. I need to get a manual for this damn car.

DaveSmed · #39 (**permalink**) 11-10-03, 05:37 PM

I think I follow your question now with the antifreeze spraying everywhere. The system should not have air in it with the exception of the pressurized overflow tank. There should be an air gap in here to allow for the expansion of the fluid when hot. The limit of the cooling system is when the fluid is hot enough to expand to fill the entire overflow tank PLUS 15 or so psi held by the cap. The pressure is key as increased pressure of a fluid raises it's boiling point by a certain amount. The cap is calibrated to release pressure after this point out of that hose to prevent component failure from abnormally high pressure in the system. This commonly occurs from overfilling the tank or blown head gaskets. While overfilling the tank is pretty self explanatory and usually self corrected, head gaskets are a little more tricky. What hapens is combustion chamber GASES force themselves into the cooling system, where they become trapped. When a pocket of air is stuck in one of the many passages in the system, it is taking up space where there once was fluid. This fluid gets displaced into the overflow tank, resulting in a situation similar to an over filed tank. BUT the gases are not pressurized by expansion as the fluid is, they get thier pressure from the compression stroke in the engine. The system remains under pressure even when cold PLUS there is an abnormally high level of fluid in the expansion tank. When you opened the cap, the air pocket expanded forcing the fluid out of the tank and all over the place. Hope this answers your question! (especially for all that typing and thinking and stuff

)

zonie77 · #40 (**permalink**) 11-10-03, 06:10 PM

It's inconsistent because it is something that is breaking! It is not a calibrated spring or a switch or anything like that.

Do the compression test and let us know what you find.

**Jesda** · #41 (**permalink**) 11-11-03, 03:49 AM

This forum kicks butt!

elwesso · #42 (**permalink**) 11-11-03, 05:16 PM

And your just now figuring this out......

You've missed some mighty fine conversations..... Goto the POST YOUR PICTURE HERE THREAD in the lounge and all will be revealed!!! You might even post your picture there to!!!!

Sorry ShadowLvr for getting off topic..... let us know how this stuff works... I hope you can figure it out, its kinda confusing!!!

ShadowLvr400 · #43 (**permalink**) 11-14-03, 06:44 PM

It can't be a head gasket, the coolant's just leaving the resevoir with the motor on or off. At this point she won't keep the coolant at all. Hoses underneath the resevoir?

zonie77 · #44 (**permalink**) 11-14-03, 11:32 PM

I'm not just trying to give you a hard time but you have to start testing things. I'm doing a head gasket replacement on my brother's SLS now and his symptoms were similar and he kept thinking it was something else until he did the compression test.
Please do the compression test.

zonie77 · #45 (**permalink**) 11-15-03, 02:27 AM

Here's a link to a picture of the block with the head off.

http://caddyinfo.netgetgoing.com/howto/nsrepair.htm

If you look at the pics on this link you'll see the coolant passages totally surround the cylinders. This is why you don't see water in the oil until the gasket is really blown. The oil drain passages are the three oval ones at the bottom of the deck.
He says the timeserts were a waste of time but we found 6 bad holes!!!! we didn't actually check all of them. With that many bad we had to timesert all of them and checking each was a waste of time.