Coolant loss/temp gauge issues

[tjsxplodr]

Ok, so, the '91 I just bought is losing coolant. I do not see any noticeable leaks, but I am also having temperature gauge issues. It never goes above cold. Could the two be related? If so, what do I need to check first?
The heat works, so I am not sure what could be causing these issues?

 

[cgbier]

There is some spray that'll show the loss under UV light.
Head gaskets are ok? Check your oil if it looks like carnation milk it's the head gasket.

 

[arco777]

Check that the thermostat is working (and is present). May want to replace it with a factory unit if some dumba$$ removed it or put a low temp stat in.

As for the coolant loss, do a pressure test on the cooling system. Also get it up to temp and look for any evidence of connections weeping. Some of the stock hose clamps don't seal very well and better off replaced with real clamps.

 

[tjsxplodr]

OK, I just got done checking the oil. It looks runny. It doesn't seem to have that chocolate color, but it also doesn't seem to be thicker like what regular oil should be. I am not certain, however. Here are some pics:

 

[mr cribb]

Simple fix first. The temp gauge sender with the one wire is bad. It is around 15 dollars or less.

The location is around the thermostat area, more located on the intake manifold. There are two sensors almost side by side. The one wire is for the gauge the two wire is to the computer.

The oil pic is fine that is normal. Blown head gasket can dump coolant into the oil pan or blow it out the exhaust. If it dumps into the oil pan it will look like chocolate milk and foamy. If you're still unsure you can smell it, it will smell sweet or (if you're brave) taste it it will taste sweet. Regular oil just smells dirty and it tastes nasty.

I suggested the taste theory because I've had lots of vehicles in the past with multiple leaks. Taste was the quick way to narrow them down.

 

[Ramblinwilly]

Another leak point that is often overlooked are "freeze out" plugs. Slow plug leaks can disappear/evaporate leaving little or no trail of a leak. As for the oil that looks fine. Like CGBIER said, the oil will be like milk.

 

[tjsxplodr]

So, i had a pressure test done. The shop said it lost pressure. Went from 17 psi to 14 psi while I waited there it was about 20 minutes. He said it could be a leak or it could be something settling inside, whatever that means. He said there are no visible leaks they could see, so he told me to drive it for one week and check the levels everyday before driving and to go from there....

 

[larrydd999]

Don't forget to check the radiator cap, and the heater core and the hoses to and from. Good luck - I've been chasing a slight coolant leak in my '94 for about a month now. It uses about a pint or so a week, depending on how much driving I do. Rather than one leak, I suspect a few very small leaks. No coolant in the oil, however...

 

[tjsxplodr]

No visible leaks from the hoses, radiator, water pump. The hoses are old so I know they should be replaced. Once I get some more money, the hoses, the radiator cap, the coolant temp sensor will all be replaced.

 

[tjsxplodr]

Well, the coolant is finally leaking visibly, just not sure from where. I was driving it to the park today. It sat in the parking lot for maybe 1/2 hr, I got back and there is a small puddle of coolant on the pavement. Not a big puddle, but enough to cause concern. So I got the X home, and sure enough, it is leaking from what appears to be the water pump area. Took some pics, but am on my phone so I'll have to upload to photobucket. How long can I wait with a blown water pump gasket before having to replace it? And if that is leaking, would it be safe to assume the pump is gone?
I have no way of telling if the engine is getting too hot because the temp gauge doesnt work......

 

[mr cribb]

Water pump is about 30 dollars or so, depending on location.

You will need to remove the fan and fan clutch assembly from the water pump first.

This can be done a few ways:

1) rent or borrow a fan clutch removal tool (recommended)

2) with the belt still on, you CAN use a chisel and hammer to loosen the fan clutch, it is also reverse thread, so righty tighty doesn't apply here.

The best answer is, keep extra coolant or water with you and check the level before you drive somewhere. Obviously get it replaced when you can.

A side note to plan for, is I would recommend replacing the fan clutch and plastic fan. I didn't and it cost me a set of heads and lots of downtime. If you don't know how old the radiator hoses are, replace them.

A wise mechanic told me "A secret to a long living 4.0 is to never let it get hot, and maintain the cooling system."

 

[tjsxplodr]

Here is a shot that I managed to take yesterday:

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[mr cribb]

I would check to see if the intake bolts are loose. That looks a little high for a water pump leak.

99% of the time when a water pump goes it leaks out the weep hole in the bottom of the pump.

 

[tjsxplodr]

Ok, will do. Thanks.

 

[tjsxplodr]

So I took it to the shop here just now and the owner showed me what appears to be a leaking intake manifold, up on top by the top radiator hose area. He said it looks like a corner of the intake manifold gasket is leaking. How hard is this to fix and how long before it HAS to be fixed?

OR, could it be a valve cover???

 

[mr cribb]

Just do it yourself. I believe it is a 10 mm and 13 mm sockets. All that needs to be done is tighten them to snug. There's 10 or 12 bolts. The torque spec is in inch pounds so a good snug by hand is pretty close to spec. Save yourself the cash and do it yourself.

 

[mr cribb]

As far as replacing the intake gasket it isn't hard. An hour or two depending on skill level.

 

[tjsxplodr]

But wouldnt it be better to replace a bad gasket vs a bandaid fix? Im being told by several people that this job is pretty extensive labor wise. I havent ever done this before...

 

[mr cribb]

Free to you to check bolts for looseness. The shops WANT to charge you for labor for an intake gasket. What if the free repair fixes your leak and the gasket is still okay?

 

[tjsxplodr]

This is true. Ok, so what would I need to pull off to check the bolts?