LO overheating constantly

[quad4paceshp]

I got a problem and need your guys help I got an 89 Calais with an LO and its been overheating constantly on me lately. It started about 6 months ago everyonce and awhile it would overheat for some reason then cool down on its own but the past 3 weeks it has been running hot and sometimes overheating really bad. I've changed the water pump the thermostat and flushed the system twice and nothing helps. most of the time it will fun hot then drop 30 degrees real fast then run hotter and drop 30 more then get even hotter and so on. I'm not as familiar yet with my Quad as I am with other engines so what could this be? I don't really know what drives the pump but my thoughts were maybe my timing chain is loose or tensioner is bad or something anyone with any thoughts I sure could use them.


Pace

[Fish]

Don't drive it hot, not good for top end. Maybe you have a blockage in the radiator or something. Figure it out, don't burn it up...

[gOoIe B]

yeah if a new t-stat and pump hasn't solved your problem, I would be keeping a close eye on the radiator. also, just because you put a new t-stat in doesn't automatically rule it out as the problem. it SHOULDN'T be the problem, but i've heard of things like that happening in the past...

[quad4paceshp]

I don't think it's the rad I've run water through it so much it could be a damn natural water spring by now the reason i think its mechanical is because of the rise and fall of the temparature in almost exactly 30 degree increments like the pump is kicking in every so often just enough to knock it down for a second plus sometimes when it gets above 230 or so if I push on the accelerator a lil it bumps it down for a sec like something grabbed this morning I ran to work 15 miles away at 160 to 180 the whole way stoped to get a paper a half mile away from my shop and when I started back up it ran 250 to 270 but like I said I dunno much about this engine and I've been reading ya'll for 6 months now and ya'll know your stuff so I guess this weekend I'll have to check the rad unless someone thinks of something else for me to check and as for tstat its been out for a week and hasn't changed anything I'm in Houston no chance of engine running to cool right now so I'll leave it out.


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[cavfan1]

Sounds like a head gasket of all things. An air bubble of some sort is making its way around the cooling system, even after you fill the cooling system up all the way after the Tstat and waterpump change. Probably combustion gasses leaking into the water jacket. Seen it before on 3100s when there head gaskets go, temp gos up, then comes down, gos up, comes down. A quick way to possibly see is to smell your coolant tank or your radiator at the filler neck. If it smells like gas or any sort of exhaust fumes, its more than likely the head gasket.

[quad4paceshp]

Well I dunno bout that either another thing is like I said I put a new pump in this weekend but I don't have any circulation because my heater core never gets hot.


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[quad4paceshp]

welp I figured it out I ripped open the timing chain cover and the timing chain tensioner shoe was cracked in half where the tensioner pushed on it so it was not helping the chain at all and the sprocket which turns the water pump was directly above that so the chain was skipping over it and not engaging it . man hope I haven't screwed the engine for a 17 dollar parts lol. oh well it just got to last till refund time gonna rebuild it and convert to an HO anyway. thanks for all the ideas guys.


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[gOoIe B]

wow, thats pretty critical? are the teeth on the pump sprocket busted up? that would be a big bummer, considering its new and everything. just feel lucky that the chain wasn't skipping over your CAM sprockets :eek: !

[quad4paceshp]

no the teeth were in fine shape there weren't any guides around the sprocket so I doubt the chain even touched it much and the one thing I was happy about is there are 3 guides all around the cam sprockets which had it nice and tight still up there but I think I'm still screwed car ran good fri and sat but isn't running so good now the heat prob did it's damage.


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[gOoIe B]

what are the symptoms now?

[quad4paceshp]

well looks like I prob got a blown head gasket or a cracked head because I have water in the oil and looks like water actually comming out of the exhaust manifold too have no clue what Imma do I don't have the exp or tools to rips off that head and I don't have the cash for a new one and don't want to get one from the jumkyard and it be broken too.


Pace

[gOoIe B]

yeah, sounds like the heat warped the head, or the gasket went, or even both. I dunno what to tell ya. its not an extremely difficult procedure for changing the head or gasket, but it is relatively time-consuming, and you have to get a lot more gaskets than just for the head.

[quad4paceshp]

well looks like Imma be changing the head gasket this weekend got a few friends that have been going to UTI here in Houston and are willing to help I think I got a fairly good idea bout it from my Haynes book and my GM service tech manual is there any special tools that I might need that I might not have? I know with the Timing chain cover only thing I had to get was the Harmonic balancer puller.


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[gOoIe B]

as long as you've got your standard tools and a trustworthy torque wrench you should be able to do the head gasket just fine.