CriticalCommonTransmission

Nissan Pathfinder: Radiator transmission cooler failure — coolant/transmission 'milkshake' (SMOD)

Radiator transmission cooler failure — coolant/transmission 'milkshake' (SMOD) is a common transmission fault on the Nissan Pathfinder on the 2005–2013 cars, and we rate it critical. Putting it right costs $4,500 to $8,000 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 36 documented faults on the Nissan Pathfinder.

Vehicle: Nissan Pathfinder
Years: 2005–2013
Gearbox: auto
System: Transmission

This page covers the Nissan Pathfinder as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Nissan Pathfinder faults36 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph of the Radiator yet. We would rather show none than show a picture of a different part.

What goes wrong

Automatic R51 Pathfinders cool their transmission fluid through a cooler inside the engine radiator. The cooler cracks internally, letting coolant and transmission fluid mix into a pink 'strawberry milkshake' that destroys the transmission's clutches — often around 100,000-180,000 km. By the time slipping or flaring appears, the damage is usually done, and the fix is a new radiator plus a rebuilt or replacement transmission. The recognised prevention is bypassing the radiator cooler with an external transmission cooler; a car that has had this done is worth paying more for.

What you would notice

Pink or milky residue in the radiator or coolant overflow bottle
Transmission fluid that smells of coolant or looks like a strawberry milkshake on the dipstick
Slipping, flaring or harsh shifting
Torque converter shudder at light throttle

How to check it

Where to look. Radiator at the front of the engine bay (internal cooler) and the automatic transmission

With the engine cold, open the radiator cap and coolant bottle and look for any pink sludge or oily film — that is the fault in progress.
Check the transmission dipstick: fluid should be red and translucent, never milky.
Look under the front of the car for an aftermarket external transmission cooler and ask for the invoice — a fitted bypass is the best possible answer.

Parts involved: Radiator.

What it costs to put right

$4,500 to $8,000 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“Has an external transmission cooler bypass been fitted?”
“Has the radiator ever been replaced, and why?”
“Has the transmission fluid ever looked milky?”

Now check the Nissan Pathfinder you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in the sources below. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them.

nissanproblems.com 'Coolant Leaks are Destroying Nissan Transmissions'
Go-Parts 'The 2005-2010 Nissan Radiator SMOD Failure: Pathfinder, Frontier, Xterra'
nissanforums.com '2006 Pathfinder radiator/transmission cooler failure' thread
RepairPal 'Pink Coolant in Radiator and Transmission Problems'

Nissan Pathfinder buyer questions

Is radiator transmission cooler failure — coolant/transmission 'milkshake' (smod) serious on a Nissan Pathfinder?

We rate it critical and common on the Nissan Pathfinder. Automatic R51 Pathfinders cool their transmission fluid through a cooler inside the engine radiator. The cooler cracks internally, letting coolant and transmission fluid mix into a pink 'strawberry milkshake' that destroys the transmission's clutches — often around 100,000-180,000 km. By the time slipping or flaring appears, the damage is usually done, and the fix is a new radiator plus a rebuilt or replacement transmission. The recognised prevention is bypassing the radiator cooler with an external transmission cooler; a car that has had this done is worth paying more for.

How much does it cost to fix on a Nissan Pathfinder?

$4,500 to $8,000 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Nissan Pathfinder years are affected?

Our research records this fault on the 2005–2013 Nissan Pathfinder. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.

How do I check for it before I buy?

With the engine cold, open the radiator cap and coolant bottle and look for any pink sludge or oily film — that is the fault in progress. Check the transmission dipstick: fluid should be red and translucent, never milky. Look under the front of the car for an aftermarket external transmission cooler and ask for the invoice — a fitted bypass is the best possible answer. Look here: Radiator at the front of the engine bay (internal cooler) and the automatic transmission