I'd buy that for 50 cause it makes sence.

I know it's corny but it's late.

Good theroy u may be onto something.

 

dang, 28 views and only one half ass response. I figured ivan would be all over this.

anyway, the honda thing is just a conspiracy theory, lol, but i think the hg theory is correct.

 

so why cant we fit the car with a more powerful waterpump?

is there no other car that will fit ours? since the RL has a better cooling system...what parts could we take from its setup..to work with ours?

 

Well waterpumps are kinda like turbos ~ they're gonna work better at certain RPM than others and they'll start wheezing at some point or just not spin quickly enough at low RPM to provide effective circulation. This was a big problem with Nissan SR20 waterpumps for instance; they worked great at low-mid RPM range, but around 6000RPM or so, they start cavitating and just spinning and making bubbles in the coolant, exacerbating the already overheating condition.

Same goes for the Legend I suppose. It works well at high RPM because Honda designs it that way, figuring hey; under most conditions Legends will be used on the freeway, or doing some high RPM driving or whatnot. Okay fine. But that means the water pump doesn't work at low RPM as well. That's a complete possibility. Honda had similar problem with their engine (cams) so they solved this by inventing VTEC to manage the compromise between high/low RPM effectiveness. This can't really work with a waterpump though because the pump's vane design is pretty much set and can't be adjusted or modified mid-use.... unless it is like one of those weird vane-twisting turbos in design but now I'm just rambling and speculating.

Anyways, this is an inherent characteristic of all water pumps... they are most effective only around a set RPM range. Maybe the Legend has an especially wide range where it needs top-notch coolant flow? Or maybe Honda just screwed up the waterpump design.

In Nissan SR20s, enthusiasts got around the problem by installing aftermarket pumps designed for SR20s... or by using 300ZX setups that more or less bolted on. Unfortunately, the C32A1 in our Legends isn't as popular with aftermarket, and it's highly doubtful we can use 3.5RL cooling systems to retrofit to our car. DV8 used the whole fricking bottom end of the motor, so he pulled it off, but unless we all do C35A1 swaps, I think it's highly unlikely we could ever make use of the RL's improved cooling system.

 

I have done a lot of thinking, and been around to read a lot of headgasket blowing threads.
Things i have observed:
1. people that live in cities blow headgaskets more frequently.(so it seems. they always talk about it overheating in stop and go)

With respect to this observation only.... Since most people in the US live in cities, then most Legends will also be driven in cities, and most HG problems will also occur in cities.

This is known as a Bayesian base-rate problem. You can't make a correct inference in this case by simply counting up the number of HG problems by city residents.

Your question is, are Legends that are driven in cities, and therefore at low rpms, more likely to have a blown HG than non-city Legends? To answer the question, you need to observe the percentage of city-Legends with HG problems, and the percentage of non-city-Legends with HG problems.

As an aside, I drove my Legend in stop-and-go traffic for several years when I lived in SoCal. I never had an overheating problem. I've also driven extensivley in the summer heat of AZ with the A/C blasting. The temp gauge never budged a millimeter. So, I think the design is probably fine.

But I agree that the waterpump might be a weak link, especially as it gets older. There is also a complex cooling-system geometry that makes it difficult to bleed the cooling system of air. Your point on mods is also relevant: mods that lower the car may change the angles of the radiator hoses, and make it even more difficult to bleed the system. Finally, the radiator itself has a poor bond between the core and the top-tank, which can result in pin-hole leaks in the system. The pin-holes allow air to get into the system, and if uncorrected can lead to poor system performance.

So, I agree with your premise that the cooling system must be carefully maintained. But I do not agree that HG problems are more likely in a city.

The Professor Hath Spoken!

 

Cap, i understand where you are coming from on the city thing.
i have experienced overheating only when my rpms are under 1500. (stop and go) never over that. which seems to indicate that this is when there i heating problems.

yes, i doubt that we can retrofit an RL one. but an aftermarket one would be nice.

two i would like to emphasize cap.

mods, not only may change the radator angle etc, but they tend to create less torque, meaning that the crank can exert less torque on the water pump via pulley. especially in the low rpm range.

i think air running thru the water pump might also cause early failure. almost everybody has replaced the radiator, cuz it leaks, meaning air has gotten in the system. i think this causes the wp to go bad early, and you also indicated that there is probably decay as they get old.

Keep in mind, this is a theory up for discussion, so far we have had some, keep it up.

 

mods, not only may change the radator angle etc, but they tend to create less torque, meaning that the crank can exert less torque on the water pump via pulley. especially in the low rpm range.

I agree this is a good discussion.

Torque is not a factor that determines the waterpump output. Rather, the waterpump pulley is attached to the pump impeller shaft. So, for a given engine rpm, the waterpump has some specific flow rate. Yes, mods have an affect on torque, but that is irrelevant to the waterpump: two engines with different torque, but each running at 1500 rpm, will have the same waterpump output in gallons per minute.

However, torque and rpm determine horsepower:
HP = Torque x RPM

And horsepower is directly related to the amount of heat produced. So, comparing two engines, both running at 1500 RPM, the engine with lower torque will produce less heat. So, if a mod reduces torque at low RPM, then that mod will REDUCE the heat load on the engine at low RPM.

So, why do we have HG problems? The best explanation I have heard is that the cylinder liners de-bond from the engine block when the engine overheats. When the liners de-bond, they expand a small amount, forcing the cylinder head to move very slightly away from the engine block. At that point, high pressure gasses from the combustion chamber can force their way past the head/block interface, and escape into the water jackets that surround the combustion chamber.

So, how do we keep from overheating? First, we need to keep the cooling system in perfect condition. That might mean that we replace the waterpump and radiator periodically -- even before we have symptoms of overheating. Second, we need to avoid trying to generate too much horsepower. (gee, that's not much fun, is it?) And third, we need to allow the engine to cool down after a period of sustained high-rpm, high-power operation. That is, after racing, don't just shut the engine off -- let the engine run at low power and mid-rpms for several minutes until the excess heat is dissipated.

I think that if someone has overheating while in stop-and-go driving, then there is something wrong with the cooling system. It could be that the radiator cap is not holding the correct pressure, the electric fan might have a defective thermostat, the engine thermostat might be defective, the radiator might be partially blocked with corrosion, the waterpump might be on its last legs, etc. etc.

 

good points cap.

hmmm...... what if we just changed the water pump pulley size? would that help?

 

what if we just changed the water pump pulley size? would that help?

Well, it might. But the car shouldn't be overheating in stop-and-go traffic if everything is working right.

So, changing the pulley size should be viewed as an alternative to diagnosing and repairing the source of the problem.

Furthermore, if you make the waterpump turn faster at lower RPM, in order to compensate for some other problem, then you will most likely create cavitation at the higher RPM's. Even if you don't cause cavitation, you will be increasing the work done by the pump, which will rob your engine of some extra power.

 

After doing the head gasket job myself I believe the problem to be the design of the engine block and the way the head mates to the cylinder sleeve. Everyone that has done this job themselves and posted the result has determined the failure to be either the #3 or #6 cylinder, lower side. I have seen a few pictures of blown head gaskets posted on the net and they all failed the same way. My BHG looked exactly like the others. For some reason the holes in the head for coolant flow are different(bigger) on the back cylinders(#3 & #6). In my opinion the design of the block does not provide enough support for the head gasket on these cylinders allowing some movement(flexing & swelling) of the gasket. This eventually allows a very small amount of hot compessed gases into the cooling system causing the water pump to cavitate and the coolant to not flow properly. Most all of the the BHG's start with a slight overheating event. I.E. cracked/leaking radiator, leaking hose and in my case, mixed the wrong types of coolant.

 

this is kinda off topic but when im in my car at normal temp i somtimes find steam comming out of my vents smelling like coolent, the hose that drains the water for the ac under the car spills out coolent.... wut could be the problem, im starting to think i dont have a blown hg my car doesnt smoke and all my spark plugs are fine, but i keep getting air in my system wut could it be?

 

Your heater core is leaking. This is the type of small event I was referring to that will lead to the Blown head gasket. Do not let your car overheat. It is probably a small leak but needs to be addressed before it turns into a big one.

 

Your heater core is leaking. This is the type of small event I was referring to that will lead to the Blown head gasket. Do not let your car overheat. It is probably a small leak but needs to be addressed before it turns into a big one.

Jetdoc, are you by chance an A & P mechanic?

 

sweet thank u soo much i love you guys !!!!
one more thing i just ordered a new heatercore from A OF A. it was origanly 390 or so i mentioned al.com and im getting it for 340 shipped!!! wut a deal. thanks guys

 

I have to admit I was seriously thinking about getting a G2. After reading about the HG probs. I'm thinking twice guys !!

 

Justin, I am an A&P mechanic. 16 yrs. exp. I am a Sr. Lead mechanic for a large overnight shipping company with purple tailed airplanes.

 

Justin, I am an A&P mechanic. 16 yrs. exp. I am a Sr. Lead mechanic for a large overnight shipping company with purple tailed airplanes.

Airborne Express, right?

 

Not Airborne,

Ok, Purple and Orange, "The world on time"

 

I'm joking. Your corporate headquarters are only 208 miles from Nashville.

 

After reading all this I think I am going to change my water pump. I have never experienced any overheating of any kind, but I guess I don't mind the preventive maintenace. I have 170,000km or 102,000miles on my car now and I don't believe the water pump has been changed yet. I haven't been able to find the service record for it (from the previous ownwer's folder). The radiator was changed though.

My question is which water pump is the best to buy. The dealer wants $179.83 Candian which is equivalent to $132.63 USD. Is that a good price and are there any aftermarket waterpumps that are of better quality?

 

After reading all this I think I am going to change my water pump. I have never experienced any overheating of any kind, but I guess I don't mind the preventive maintenace. I have 170,000km or 102,000miles on my car now and I don't believe the water pump has been changed yet. I haven't been able to find the service record for it (from the previous ownwer's folder). The radiator was changed though.

My question is which water pump is the best to buy. The dealer wants $179.83 Candian which is equivalent to $132.63 USD. Is that a good price and are there any aftermarket waterpumps that are of better quality?

Given that the cooling system needs intense attention on our Legends, I wouldn't compromise with remanufactured and/or aftermarket parts. $132.63 is a real good price for OEM, the lowest I can get one (locally) is $200.

 

Thanks Kasteman,

I appreciate the advice and you are probably right.
I think I may be able to get it for about $100 USD after discount. I'll find out this week.
I was told that the 1991-1992 sedan part number is the same as 1993-1994-1995 coupe part number. I asked because I was curious to see how many part numbers they had for the 1991-1995 Legend. Maybe there could have been a new part number that superseded the old one.

 

Justin, I am an A&P mechanic. 16 yrs. exp. I am a Sr. Lead mechanic for a large overnight shipping company with purple tailed airplanes.

Jetdoc, i know which one you're talking about. i'm going to school right now to get my A & P license here in CO. that's what i did in the air force, and it seemed only natural to continue with it.

 

i just wanna say thanks one more time to u guys, with out ur help i probably would of invested in a new head gasket costing me over 1600 dollers, now i know the true problem and i only had to spend 340! thank you so much guys, go to show boys do ur homework before trying to resolve the problem!!!:bowdown: :bowdown: :bowdown: :bowdown: :bowdown: :bowdown: :bowdown: :bowdown: :bowdown: :bowdown: :bowdown: :bowdown: :bowdown: :bowdown: :bowdown:

 

I have to admit I was seriously thinking about getting a G2. After reading about the HG probs. I'm thinking twice guys !!

If you want something nice, you often have to pay a nice price.