Hello all,

My '07 DB9 smells of coolant at the front of the car, obviously near the radiator. I add a couple ounces of coolant or water every 100 miles or so. The kicker is I can see no leak after taking off the top panel and searching around with a flashlight. I can see all the way down to the bottom tray and it is dry as a bone. I can only smell coolant at the very front of the car, no smell inside the cabin (heater core) and the oil isn't milky.

I plan to have a pressure test done to figure it out, but wanted to see if anyone had any ideas?

Thanks!

 

Plastic radiators are known to only leak when hot and under pressure. Another place to look is around t-stat housing and overflow tank. Overflow tank is not the one where you add coolant, it will most likely be on the inner fender either in the engine bay or between the inner fender and outer fender, not sure on a DB9.

 

Thanks, I'll check those other areas. Another odd thing is that the system is definitely keeping pressure; the reservoir cap still "pops" when removing it when cold and I've had some coolant spray out when I *thought* the engine was cool enough to check.

Thanks again.

 

Sounds like you are smelling boil over, sometimes happens when car gets real hot.

When was the last time the coolant was changed?

 

It's weird, I can smell the coolant just about every time I take her our and get her up to temp. The coolant was last replaced 7/2013, so it's definitely not to the 5yr/100k miles point.

 

If you have a small leak,and I assume you have since you add coolant, you will smell the coolant even if the leak is so tiny that the water evaporates before it collects on the bottom tray.

 

Yeah, I figure I have a leak somewhere in/around the radiator (since that's where the smell is by far the strongest), but the hole is so small (and possibly top-facing) that nothing is physically spewing out. I've been looking for orange on/around the radiator but haven't seen anything. Pretty odd, I'll see what the pressure test says.

Thanks!

 

On a LHD DB9 the expansion tank is behind the driver's side wheel arch. It's a sizable tank that has an overflow pipe.

 

When my Jags radiator failed, it only leaked when it was hot. So pressure test it and I fear you will find the leak.
I hope it is just boil over and not a bad radiator.

 

Thanks for the advice, gents. There has to be a leak, it's just weird that it's nowhere to be found. As for the UV dye, the coolant itself is orange so I would think it should be easy enough to see.

 

I have the exact same issue. Don't smell it every time, but I do get a coolant whiff every now and then. It's been going on with this car since my buddy owned it (and I put the majority of the miles on it...). That dates back to 2010. I'll pressure test the radiator again this spring, but to date nothing has been found.

 

If you smell coolant you have a leak. Note that a very small leak, one that evaporates the moment it hits the hot engine, is extremely difficult to find. The best method is to pressurize the radiator, and even then you might not find it. Finally a small leak hitting the hot engine will smell just about the same as a big leak.