hi there i have an oil leak underneath the radiator what would it be do you think

Transmission fluid leaking from the cooler in the radiator maybe?

 

Only oil at the radiator, unless you have bigger problems. Was it directly under? Is the fluid quite runny at have a tinge of red?

It could also be coolant that's picked up dirt etc on the way. I know people who've confused coolant for oil before.

Should be able to tell by feeling it

 

If it is on the drivers side it will most likely be power steering fluid leaking from a connection between the flexible fluid line and the steel line the flexible line feeds on to. This particular joint is located quite close to the bottom of the radiator on the driver's side. There is just one hose clamp that holds the line on and it can lose tension and allow fluid to escape under pressure at the joint. Fitting a second hose clip on the joint and tensioning both clips correctly will stop it happening again. Check your PS fluid level because if it is down the joint described above is the possible culprit especially if you have what looks like an oily substance dropping on the right front side of the vehicle beneath the bumper.