Slight Coolant Smell of Exhaust Gas

[BEERMAN]

Excuse me,

When the vehicle is running, the coolant seems to be pressurized enough to spill out through the radiator cap, and I've detected a faint exhaust gas / gasoline odor in there as well.

I have tried starting the engine with the radiator cap off and without seeing any white smoke, and I have also tried running the engine with no visible bubbles in the cooling system.

What do you make of this, and how can I begin making a diagnosis?

[Craigbelont]

Find a mechanic that has a gadget that can detect exhaust gas in the coolant. You say you have a coolant leak?

[BEERMAN]

The radiator is about halfway full and will spit out anything more than that; I lose a bit, but I guess it's just from the cap. The temperature readout never deviates from the white.

[Craigbelont]

I noticed that the SD1 kinds had an overflow bottle; do you? The white, see-through ones make sure the radiator header tank is always full with coolant.

[BEERMAN]

I don't have one but keep intending to get one!

[BEERMAN]

I was wondering if the Land Rover Freelander I's expansion bottle, which is round and has a single foot for bolting, might work with the existing single bolt for the brake hardware (or with a short fabricated bracket).

[Mistral]

Gasket Combustion Leak Test Kit / Universal Petrol & Diesel Block Tester BT-500 | eBay

[BEERMAN]

OK, so I used a kit today and saw that the liquid changed colors from blue to green after being exposed to sunlight.

Since I haven't seen any white smoke or unusual noises, do you suppose the intake manifold gasket or the head gasket is at fault?

[keithmerc220]

The head gasket, alas, seems to be the culprit. Before taking the heads off, you'll want to take the manifold gasket off so you can check it.
Although I am no expert on the Rover V8 engine, I have noticed that it often has head gasket failure and coolant pressure issues.

Right now I'm investigating the same problem you are. Having coolant leak out with no additional warnings.

The head gasket allows the cylinder pressures to escape into the water system without the water reentering the cylinders. The coolant pressure is much lower than the cylinder pressure. Therefore, fortunately, there is no "white smoke" coming out of your tailpipe.
If steam was really coming out of the exhaust, I wouldn't recommend stopping there and only replacing the head gaskets.
After removing the engine's cylinder heads, I saw that one of the studs had loosened its threads, which caused the block face to rise around the stud holes, revealing a leak from the engine's rear cylinder into the cooling system.

[BEERMAN]

I've been debating whether or not to repair it myself, and after reading the instructions and seeing a few videos, I don't think it'll be too tough.

[Chrishazle]

I am now addressing a similar problem with the Rover SD1 Vitesse engine in my TVR 350i. I thought you would find this PistonHeads site useful.

Wedges - PistonHeads UK - Page 1 - Possible Head Gasket Failure

If you have basic technical skills, removing the heads from a P6V8 engine is not a tough process.