posted by
someone claiming to be Zuda
on
Thu Oct 24 13:09 CST 2002 [ RELATED]
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I changed all the smaller coolant hoses on my recently acquired '94 945T. The oil cooler hoses were on the verge of failure and one of the heater hoses looked original (so I replaced them both).
Ever since then I have been fighting coolant leaks, some fast others slow. The most recent one was at the firewall connection, sanded down any gouges that I may have put there when I cut the old hose off, and adjusted/tightened the clamp on the lower heater...checked my coolant level every day and it stayed constant. No more leak (there). The coolant level when the engine was cold was at the seam in the tank (say mid-way between Max/Min) and when it was hot the level was maybe 1/2 -> 3/4" higher.
- This level of expansion is normal right?
Tuesday I checked the level again (cold) and it was down about 1/2" from the seam...looked under the hood and noticed that the starter had some wetness to it, felt around the heater control valve and it too was a little wet... New heater control valve received today from fcpgroton and it's going to be installed tomorrow. I also noticed some coolant drops on the plastic radiator ends, they were apparently coming from the junction between the metal/plastic. Haven't seen any drops lately, although what looks like light gray dust does accumulate on the "plastic reinforcment ribs" (not sure how to describe them), I brush them off every other day but they come back. Could this be dried coolant or is it just regular dirt accumulation from driving?
The car doesn't overheat, the temp guage runs at the 12:00 position. Although on a long (3hr) leaf-peeping trip the guage would drop down ever so slightly but enough to notice. Haven't driven the car much since then (two weeks ago) to notice any movement.
So my question(s):
- If there is air in the system, does it bleed off somehow automatically?
- Would an air bubble in the system cause the temp guage to fluctuate ever so slightly?
- Would an air bubble increase the pressure in the system to the point where leaks may pop up?
In any case, after hearing about the plastic/metal radiator failing, I plan on replaceing it with an all metal one. The heater control valve is coming out tomorrow (or maybe late tonight when the wife gets home...).
Thanks for listening,
Zuda
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posted by
someone claiming to be steve
on
Thu Oct 24 15:49 CST 2002 [ RELATED]
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Some thoughts:
1. Thermostat orientation and air bleed. The thermostat has a small air bleed hole that needs to be "up" when re-installed.. This allows air from the head to bleed out the top hose, into the radiator, thence into the coolant bottle. I have found, though, that the best way to ensure that it bleeds correctly is merely to loosen the thermo housing until coolant runs out, then tighten.
2. Radiator. The radiator is a normal change-out item at the eight year point; after that you are running on borrowed time. I installed an all-metal radiator and found it both heavy and prone to corrosion (with Dexcool); I replaced it with an OEM plastic unit and it works fine. The plastic radiators are superior with one exception: they need to be changed every eight years or so.
3. You were wise to change ALL the components, since they all age and fail around the same time. For a coolant, try the new Zerex Glysantin G-05 from Autozone, which looks to be the best replacement for Volvo OEM blue.
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You're on the right track. The heater control valve and the radiator are both common failure items on these, so it's best to replace them in a controlled setting rather than on the side of the road or after a 2-hour tow.
The new replacements are better than the original parts were for these items. There shouldn't be any real issues with bleeding air out of the system. Run it with the radiator cap off, after filling up, with the heater on full. When any bubbles stop, the system should be completely full.
The presence of air won't make for more pressure in the system- the radiator cap controls system pressure and doesn't care whether it's air or water pressure behind it.
Some fluctuation in temperature is normal anyway. There's probably a bit of difference between the temp where your mechanical thermostat opens and the electric fan thermo-switch turns on. I'd expect a bit of difference between the temp on the highway and sitting, idling in traffic. As long as it's in the normal range and you aren't losign fluid, I wouldn't worry about it.
--
Rob Bareiss, New London CT ::: 86 244DL, 87 244DL, 88 744GLE: 625K total
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Just a word of confirmation for Aye Roll's advice about changing the radiator. I had the top neck snap (classic!) on my '90 in July and by sheer luck was left with enough of a stub to clamp onto so as to limp home. It was a nervous moment since the coolant goes so fast when this happens that a warped head is a distinct possibility, and of course this was a 95 degree day on the freeway with A/C on full blast.
Replacing it was a snap at home, so much so that I immediately ordered another and did the '87 which miraculously still had the original radiator, though weeping dangerously at the tanks like yours.
Opinions vary on this, but I replaced both with metal 3-row models since my feeling is that metal is a lot less likely to cause a potentially head warping blowout. Put another way, in 22 years of driving Volvos the plastic radiator was my first experience with instantly blowing out all my coolant. A radiator should not require routine semiannual replacement like tires or hoses, hmmm?
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Absolutely, change out the radiator. Your "gray dust" certainly sounds like dried coolant and is in the right place to be coming from a seam or crack. I replaced my '94 945's 1.5 yrs ago and could only find a plastic tank at the time. Apparently, I overtightened the hoses on the radiator necks and my new $300 radiator lasted less than 2 years before a neck broke off. It has a shiny new all metal one now, only a 2-core but that should be OK since I don't race or tow.
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Bob Kraushaar '94 945T, '91 940T, '88 240, '94 F-150, '68 Shelby GT-500 KR
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posted by
someone claiming to be Zuda
on
Thu Oct 24 15:51 CST 2002 [ RELATED]
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Thanks for your thoughts. I'm annoyed that I didn't change the radiator when I did the hose change, dropping the coolant is such a PITA. Easy job, just a pain.
Any tricks/hints to replacing the radiator? I'm thinking the transmission cooler is going to add complications to such an easy job. My '90 240 is a piece of cake....
Where is the best place to buy a Nissens, best being cheapest? I'm fond of fcpgroton because they are within driving distance if I need the part ASAP, I like them even better because when they ship to me in RI there is no tax (but there is shipping, so I'm paying for the convenience). :)
Rob, thanks for the "new" FCP link, it's different for sure. Thank God (or Nick) for the search feature!
Later,
Zuda
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