MajorCommonCooling

Honda Odyssey: RA-Series Radiator Plastic Tank Cracking and Coolant Loss

RA-Series Radiator Plastic Tank Cracking and Coolant Loss is a common cooling fault on the Honda Odyssey on the 1998–2003 cars, and we rate it major. Putting it right costs $520 to $1,000 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 45 documented faults on the Honda Odyssey.

Vehicle: Honda Odyssey
Years: 1998–2003
Fuel: petrol
System: Cooling

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

All Honda Odyssey faults45 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

The RA-generation Odyssey (1998–2003) is fitted with an aluminium radiator using injection-moulded plastic end-tanks. The tanks are susceptible to cracking at the crimped joint after 15+ years of thermal cycling. Failure can be sudden, dumping coolant rapidly, or progressive with a slow weep. On the J30A V6, rapid coolant loss leading to overheating risks warping the aluminium cylinder heads — an expensive consequence if not caught promptly.

What you would notice

Coolant puddle beneath front of vehicle after parking
Coolant level dropping in reservoir between checks
Temperature gauge rising above the midpoint
Steam or sweet smell from engine bay

How to check it

Where to look. Front of engine bay — radiator plastic side-tanks and core seams

Examine both plastic side-tanks for cracks, especially at the crimped joint with the core.
Run the engine to operating temperature and re-inspect for seeping at the tank seams or hose connections.
Check the lower radiator hose for softness which indicates internal coolant degradation.
If a workshop inspection is possible: With engine fully cold, remove the radiator cap and inspect coolant colour and condition.

Parts involved: Radiator.

What it costs to put right

$520 to $1,000 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 the radiator been replaced or repaired?”
“When was the coolant last flushed?”

Now check the Honda Odyssey 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 published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.

Honda Odyssey buyer questions

Is ra-series radiator plastic tank cracking and coolant loss serious on a Honda Odyssey?

We rate it major and common on the Honda Odyssey. The RA-generation Odyssey (1998–2003) is fitted with an aluminium radiator using injection-moulded plastic end-tanks. The tanks are susceptible to cracking at the crimped joint after 15+ years of thermal cycling. Failure can be sudden, dumping coolant rapidly, or progressive with a slow weep. On the J30A V6, rapid coolant loss leading to overheating risks warping the aluminium cylinder heads — an expensive consequence if not caught promptly.

How much does it cost to fix on a Honda Odyssey?

$520 to $1,000 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 Honda Odyssey years are affected?

Our research records this fault on the 1998–2003 Honda Odyssey. 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?

Examine both plastic side-tanks for cracks, especially at the crimped joint with the core. Run the engine to operating temperature and re-inspect for seeping at the tank seams or hose connections. Check the lower radiator hose for softness which indicates internal coolant degradation. If a workshop inspection is possible: With engine fully cold, remove the radiator cap and inspect coolant colour and condition. Look here: Front of engine bay — radiator plastic side-tanks and core seams