Problem: Coolant smell from engine but no smoke or water in oil (see pics)
 

Hi guys,

great forum and community! I got my first dodge (99 Ram 1500 2wd 5.2L V8) last week and it wasn't in perfect shape and required some work. I just changed the rear speed sensor (followed everyone's advices) and it fixed my speedo and the ABS and brake light.

I am not a mechanic, I work in video games. However I am familiar with tuning, I also have a 300zx turbo in original like conditions.

My next Ram issue is a coolant smell from under the hood. Immediately I suspected a head gasket. But I then investigated further:

• No water in oil (not milky or clear)
• No oil in coolant tank
• No white smoke when pressing the gas
• Tested to turn on the heat inside at max to see if it would be related to the heater, but there is not any coolant smell from inside.
• No drops on the ground

I went through every single thread regarding coolant smell issues and the plenum problems. I first thought it was the head gasket, but it may look more like a coolant loss or plenum problem.

I took several pics of the engine today, it seems to be wet in a few spots. I thought maybe those are clues to a plenum problem? Please take a look and would really appreciate your advices:

Here is a shot from the passenger of the engine. The valve cover seems leaking?
http://digitalcreation.ca/misc/dodge/01_engine-left.jpg

Close up of the valve cover leak.
http://digitalcreation.ca/misc/dodge...ine-left-B.jpg

Passenger side of engine
http://digitalcreation.ca/misc/dodge/02_engine-left.jpg

Where I stand here and get close, this is when I get the strongest coolant smell.
http://digitalcreation.ca/misc/dodge...left-smell.jpg

I noticed a host from the rad seems a little wet.
http://digitalcreation.ca/misc/dodge...ront_hoses.jpg

Hard to see on the pic, but no oil in coolant. The truck has orange coolant btw.
http://digitalcreation.ca/misc/dodge...ne-coolant.jpg

If you look under on the passenger, you will see that it's also wet.
http://digitalcreation.ca/misc/dodge...left_under.jpg

This is the driver side of the engine, seems to be quite messy. Look also at the splash.
http://digitalcreation.ca/misc/dodge...gine-right.jpg

Same, but from a different angle.
http://digitalcreation.ca/misc/dodge...gine-right.jpg

Driver side of the engine, look at the valve cover on that side too.
http://digitalcreation.ca/misc/dodge...gine-right.jpg

Close up view of the driver side (valve cover)
http://digitalcreation.ca/misc/dodge...gine-right.jpg

Driver side, top shot also showing the intake kinda wet.
http://digitalcreation.ca/misc/dodge...ght_intake.jpg

Driver side, intake is wet.
http://digitalcreation.ca/misc/dodge...ht_intakeB.jpg

I would really appreciate any input. The engine has 175 000 KM and seems to be running well.

Thanks
Pat

Have you tried doing a pressure test to see where the coolants coming from? You can rent one from your local auto parts store.

I have not tried yet. Just fixed the Rear speed sensor and now moving to this one.

If the plenum is almost a sure problem, maybe I should do a full tune up. Plugs, cap, wire, valve cover gaskets and all at once. How can I tell if its a head gasket? if it doesnt smoke, or its not milky. This should be signs its something else right?

There are two places that you need to check. I had this same problem and both of them are really hard to spot. First, check your thermostat housing. If that gasket is leaking onto the top of the intake, you will smell the coolant but never see the leak b/c it burns off. Simple to do, replace the gasket and thermostat at the same time and use some blue RTV that is for the coolant system.

Second, check your water pump gaskets and timing cover gaskets. My timing cover gasket went out for no reason. If you see evidence of coolant leaking down the front of your block, its prolly either one or both.

By the looks of your pics, I would bet on it being your thermostat gasket. When leaking it will soak the intake, go all the way around the valve covers and usually make it look like you have a blown head gasket.

+1 on t-stat housing. Had the same exact issue last year. Look down from the top with a flashlight, directly above the t-stat housing (front of the intake manifold). Mine had small pools of coolant around the housing, that would burn off, but some would make it to the belt and get tossed all over the engine. Was a real mess.

If not there, inspect closely around the water pump.

As far as the valve covers go, mine looked similar, until I took a ratchet and socket and tightened them...over the last 10, 11 years, they'd loosened up a bit on their own.

The valve covers will loosen up in as little as 3000 miles. When I changed my valve cover gaskets I had 5 on each side that were barely touching the valve covers. They were torqued to about -5 inch pounds.

awesome, I will be looking into it over the week-end. Thanks for all the tips and advices, this is really helpful.

Regarding the Valve covers, I should probably tight them up again. How hard are we suppose to torque those?

thanks

I will throw something else out there that just this weekend happened to me. I was leaking coolant and isolated it to the t-stat housing area as I saw the pooled coolant in the low areas of the intake. I pulled the housing, replaced the t-stat and gasket using a generous amount of silicon and put it all back together. And it was still leaking. So I tore it apart again, this time being very meticulous about the clean up and drying everything off before applying the silicone and gasket. Still leaking.... Then it dawned on me what the problem was, the heater hose just next to the t-stat housing. I didnt tighten the clamp down enough and it was leaking.

Dang. That's gotta piss ya off when you discover that.

95 inch pounds. That isn't much past finger tight.