On my 99 Voyager, 3.0, I have a leak in a pipe that comes from under the fuel injector housing. On the drivers side, the lower radiator hose and a heater hose connect to a pipe that leads to this pipe. The pipe then goes under the fuel injectors to the passenger side where the water pump, etc are. This pipe seems to be leaking and I need to know how to replace it. My job is on the line so time is of the essence. Please help!

if you follow the pipe does it go towards the transmission ? if so it's for the trans cooler. If not it will be the escape hose incase of overheating/to much pressure in the coolant system , if you go to a parts retailer like autozone they will have the part named on their data system , its a bit difficult without seeing vehicle to name parts . although you have given a good description, the lower rad hose carries cooled coolant so i would think it's the trans cooler but check at autozone or similar

Well, the trans is on the left or drivers side of the van.
If the trans were leaking fluid it would be red.
Orange could be radiator coolant. It could be a hose or the water pump.
Someone will have to narrow down where it is coming from.

I have the same problem (01 Galant) replaced the water pump, radiator, thermostat housing, the hose, its the pipe under the car(near drivers seat) , going from the water pump to the thermo housing > What is that pipe called? anyone?

If you have the V6 (2.5L) engine, be advised: it's a wearing task. Just getting to the radiator drain plug can be a problem without a 3/8 inch drive ratchet, a 3 inch extension, a universal joint. and a 19 mm socket. The drain plug is on the passenger side of the radiator on the engine side. The 19mm socket will fit over the drain plug to turn it open.
The coolant plumbing on this engine is the craziest I have ever seen. The thermostat is on the rear face of the engine (where the radiator hoses connect), but not on the upper hose where it connects to the upright pipe with the radiator cap on it, it is on the lower hose connection. Pull that hose off the housing, and remove the three bolts holding the thermostat housing to the engine. It will help if you first remove the big air inlet hose from the air filter housing to the throttle body. I wouldn't even bother with the thermostat till you have found the leak. Is any coolant leaking from the front of the engine, dripping off the bottom behind the crank pulley? That would be a water pump problem or SEAL, an o-ring on the back of the water pump. Now get on the driver's side and look around on the rear of engine nearest the firewall where engine and transaxle mate. Look down there for signs of coolant coming from rear of engine and running down onto the transaxle case. There is a metal pipe laying in the valley below the lower intake manifold, connecting the water pump at the front and the rear housing where the radiator hoses and heater hoses connect. This metal pipe uses an o-ring for a seal into the water pump, and the same size o-ring to connect to the rear housing. If one of those o-rings is leaking, you have a big problem getting to it.. I took the rear housing off once (never again!), Now I'm taking the water pump off to fix a leak. The water pump is run by the timing belt, so the front of engine needs to be stripped down, and the timing belt removed to take off the water pump. That metal pipe is held in place by a bracket with one bolt on the rear of engine; it may require taking the lower intake off (again) to get to both of those pesky o-rings. I hope you don't have the same problem, and if you have the 4 cylinder engine, the thermostat is a snap to replace, plus you don't have that crazy plumbing problem.

check top radiator hose goes to thermostat housing sound like its leaking if your engine leaking from left driver side on top of engine it has to be top radiator thermostat hose leaking.wait until engine cool down replace top radiator hose see if coolant leaking still occur if so you could have radiator leak.

Yes you do, the following info explains the necessary procedure.



Click here to enlarge image.

Click here to enlarge image.

1. Properly relieve the fuel system pressure.
2. Disconnect the negative battery cable. Place a clean drain pan under the radiator, open the drain **** and drain the cooling system.
3. Remove the air cleaner assembly and the fuel injector sight shield.
4. Disconnect the cables from the throttle body and mount bracket.
5. Remove the coolant recovery reservoir.
6. Remove the inner fender electrical cover on the right side.
7. Remove the right rear crossover pipe heat shield.
8. Disconnect the fuel lines from the fuel rail and from the cable bracket.
9. Remove the alternator and brace.
10. Remove the throttle body cable mounting bracket with the vacuum lines and disconnect the vacuum lines.
11. Tag and detach the electrical connections at the throttle body and both banks of fuel injectors.
12. Disconnect the vacuum hoses from the canister purge solenoid valve and transaxle module and intake connection.
13. Unbolt the power steering pump and move forward. DO NOT disconnect the fluid lines.
14. Tag and disconnect the spark plug wires position lay aside.
15. Disconnect the coolant bypass hose from the intake manifold.
16. Remove the solenoid valve mounting bracket and power steering support brace from the intake manifold.
17. Disconnect the heater pipes from the intake and front cover.
18. Remove the alternator support brace from the intake.
19. Disconnect the upper radiator hose from the housing.
20. Remove the thermostat housing and thermostat from the intake.
21. Detach the electrical connector from the temperature sensor and sensor switch.
22. Unfasten the intake manifold bolts, then remove the manifold as an assembly. Remove and discard the gaskets.
23. If separating the upper manifold from the lower, proceed as follows:
24. Remove the fuel rail and fuel injectors.
25. Detach the coolant sensor switch.
26. Remove the manifold end cap cover.
27. Remove the upper intake manifold and throttle body assembly from the lower manifold. Remove and discard the gaskets. To install:
    
28. Thoroughly clean all gasket mating surfaces.
29. If replacing the upper manifold, proceed as follows:
30. Apply a 1⁄16 in. bead of Loctite® Instant Gasket Eliminator 51845 or equivalent to the lower manifold mating surface. Make sure to circle all bolt holes.
31. Carefully lower the upper manifold and throttle body assembly onto the lower manifold.
32. Tighten the upper manifold retaining bolts to 19 ft. lbs. (26 Nm).
33. Install the manifold end cap cover and the coolant sensor switch.
34. Install the fuel injectors and rail to the manifold assembly.
35. Clean the mating surfaces and install the intake manifold gaskets and seals. Apply sealer to the ends of the of the intake manifold seals.
36. Position the intake manifold and apply a suitable thread lock compound to the bolt threads. Tighten the retaining bolts to 88 inch lbs. (10 Nm), twice, in the sequence shown in the accompanying figure.
37. Attach the electrical connector to the temperature sensor and sensor switch.
38. Install the thermostat housing and thermostat with a new gasket.
39. Connect the alternator support brace to the intake.
40. Install the solenoid valve mounting bracket and power steering support brace to the intake manifold.
41. Connect the heater pipes to the intake and front cover.
42. Attach the coolant bypass hose to the intake manifold.
43. Install the power steering pump support bracket and tighten to 37 ft. lbs. (50 Nm).
44. Install the spark plug wires on both sides.
45. Install the belt tensioner pulley and tighten to 33 ft. lbs. (45 Nm).
46. Install the power steering pump.
47. Connect the vacuum hoses to the canister purge solenoid valve and transaxle module and intake connection.
48. Attach the electrical connections at the throttle body and both banks of fuel injectors.
49. Install the alternator and brace.
50. Connect the throttle body cable mounting bracket with the vacuum lines.
51. Install the right rear crossover pipe heat shield.
52. Install the cables to the throttle body.
53. Connect the fuel lines to the fuel rail and mount bracket.
54. Install the inner fender electrical cover on the right side.
55. Install the coolant recovery reservoir and upper radiator hose. Fill the cooling system.
56. Install the air cleaner assembly and the fuel injector sight shield.
57. Connect the negative battery cable.

get a mirror and a light, works for me

I have had a similar problem with my son's Accord. You are lucky that your son knew to stop immediately, this happened to my son and we ended up having the head rebuilt.

A leak may exist but not show up until there is adequate pressure or, you may have a blockage that caused excessive pressure.

We once had the radiator leak which was nearly undetectable in his Accord, check for moisture in the trough where the radiator sits by looking down the inboard side of the radiator with the hood up. You may need a flashlight. Radiators are available at auto parts stores for about $100 and easy to replace. Replace the thermostat, cap and as many hoses as you can at the same time.

Another problem we had was the radiator cap had come apart and leaked periodically.

If the thermostat stuck, this could have caused a temperature and pressure surge explaining the now-you-see-it-now-you-don't leak. A faulty fan, or fan switch could also cause a periodic temperature surge.

The leak could be coming from the thermostat housing which is on the passenger side of a 4 cyl engine, or from the upper or lower radiator hoses or the two heater hoses. The water pump is on the drivers side and connects to the thermostat housing through a metal pipe with O-ring seals.

Exploded view of the thermostat arrangement—3.8L engines

Drain coolant at the radiator drain. Remove air intake hose and MAF sensor assembly. remove throttle cable bracket and disconnect cable linkage. Remove throttle body bolts and disconnect coolant hoses to throttle body. Loosen heater hose pipe and remove heater hose from rear of pipe. Remove radiator hose from thermostat housing. Remove top thermostat housing bolt. Loosen and almost remove lower thermostat bolt. You will need to slide your wrench and hand under the exhaust crossover pipe to gain access. Loosen the bolt until you can remove the thermostat housing, it should be slotted to clear the bolt. Replace the thermostat and reassemble. Bleed cooling system using the two bleed screws (one on thermostat housing and the other on the passenger side of the engine where the heater hose pipe comes out above the water pump.