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Block Test


CHL2T

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Went to look at a 98 STS today with 138,000 that was/ is in near perfect condition (of course) and while doing the block test I found the following....

Owner had started the car before we got there, car was warm but not up to temperature.

No pressure under the cap.

Applied the tester and pumped it up and created a vacuum, fluid stayed blue and perfect and I thought we were home free.....

Started the car and let it reach operating temperature and once it did there was some bubbling in the tester and the fluid proceeded to turn green.

Turned car off, removed tester and took it for a quick drive around the block and up some hills, There was no change in temperature via the gauge.

Returned to the drive way and re tested and the fluid turned green immediately.

It was at that point that I told the owner that I suspected the HG was on it's way out and that I couldn't take the chance on a complete failure. He was not disappointed and was genuinely appreciative on the information that I gave him on the car. He sent me an email after and said he was going to try Bars stop leaks and I am not sure that's going to do anything for it but haven't said so........

What do you guys think?

Thanks!

Don't let your first ride be your last ride in a Cadillac!

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If it tested positive for combustion products in the coolant, it's got head leakage. It's about the right age and mileage to have gone 7 years without a coolant change, a history very common with this type of problem.

The guy changed the coolant just before he drove it over for you to look at, and it took a little driving to get the coolant to test bad. I hate that.

The usual problem with a car with this history is that a head bolt has pulled out. Bars Leaks is for casting porosity, seepage leaks in hose clamps and under gaskets, pinholes in radiators an such. It hardens on exposure to air an can seal tiny leaks to the outside; the pressurization that it holds is typically 15 psi. This kind of thing will *never* hold head leakage.

In the days of iron engines, a warped head could allow a bit of head seepage. Sodium silicate in the coolant could form a "water-glass" seal in some cases that would sometimes patch a really old low-compression iron-engine engine that was never asked to supply much torque. Or not. Not so on aluminum engines or any high compression engine, or an engine that was ever put under significant load. If a head bolt it pulled out? Just don't go there.

How much would you pay for *any* used car that used sodium silicate to seal head leakage?

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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cadillac Jim i didn't read

"The guy changed the coolant just before he drove it over for you to look at, and it took a little driving to get the coolant to test bad. I hate that."

but if thats the case, he probably knew what he was doing and I would let the world around you know.

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Unless you can buy the car for a very cheap price and then repair it yourself, I'd steer clear of it.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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Unless you can buy the car for a very cheap price and then repair it yourself, I'd steer clear of it.

agreed. Only purchase it if you want to be prepared for the coming events with it. Great testing.

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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Thanks Guys,

He wanted 2700 for it and had it not tested bad, it would have been worth the asking price.

Oh well, for now, I am just going to fix the heater core in the 95 and keep it going as it has really been a good car.

I'm still on the lookout for an 04 and they are out there, just hard to get cause they go fast when they pop up

like this for instance, http://seattle.craigslist.org/see/cto/4512339270.html

not a seville but........

Don't let your first ride be your last ride in a Cadillac!

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cadillac Jim i didn't read

"The guy changed the coolant just before he drove it over for you to look at, and it took a little driving to get the coolant to test bad. I hate that."

but if thats the case, he probably knew what he was doing and I would let the world around you know.

Noooooo.... tell me it isn't soooo...

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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Gonna go look at a 04 DTS tomorrow, a little more expensive but in near perfect condition. Original owner, normal oil consumption, dealer maintained, many new parts, always garaged and so on and so forth....

http://seattle.craigslist.org/est/cto/4511007656.html

Don't let your first ride be your last ride in a Cadillac!

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Installed a new heater core in the 95 and decided for the heck of it, to do a block test......

No anti freeze/ coolant, just water and car up to operating temperature.....

Fluid turns green immediately,,,,

My daughter drove the heck out of this car for three years and this being the first time that I have done a block test on it, I assume that it has not happened all of a sudden and in fact has been this way since I acquired it....

The car doesn't overheat but it does fluctuate between 220 and 210 regularly.........

Am I to assume that this block test is only a suggestion that there may be a problem?

Did I scare the owner of the 98 that I looked at needlessly by telling him it was on the way out when it could still get many more years of trouble free service?

I am planning on selling the 95 to my renter with full disclosure, and since I can, I will monitor the car while he has it and see if the "failing HG" gets any worse or just remains the same....

Don't let your first ride be your last ride in a Cadillac!

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It's possible to have small amounts of combustion byproducts in the coolant without a pulled head bolt. <armchair pundit> In fact it seems to me that minor head leakage from acid coolant around a head gasket seal can increase head leakage so that significant amounts of acid coolant get into the head bolt wells, and that could be a possible course of events that leads to pulled head bolts.</armchair pundit>

Or, the test could be a false positive because of burnt coolant from the coolant being low.

Whatever, I would flush the system well (pulled thermostat, reverse-flush block, heater core, and radiator; a radiator shop can do this), put fresh 50-50 into it, drive it for a week, and test again. If it continues to test positive for combustion products, you may have up to a year to plan what to do about it.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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I did drive mine for about a year after it started using up coolant. I carried extra with me at all times. I even made a trip from Kansas to Kentucky and back without having to add coolant one time after it had started the problem. I continued to drive it until I couldn't even make a 20 mile trip without over heating.

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If the head gasket has a porous leak, a little bars will find its way back into the head gasket, mix with a little carbon from combustion, rust, and form a seal. Unfortunately we have no way of knowing if the bolts are pulled or not, so the head nuisance leak remains an unknown for it's complexity. I have seen photos of bars successfully plugging porous head gaskets. I think someone posted one on caddyinfo too!

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