Mercruiser Thermostat housing
 

Probably a dumb question but.........

I was changing my thermostat the other day and noticed the thermostat housing was looking a little ratty (2000 454 Mag MPI). Order a fancy new stainless one from a suppliers that said OEM replacement. Got it and noticed the mounting flange was significantly thinner so had to get some smaller SS mountings bolts. No biggie, but then when trying to mount it i realized I had to clearance the mounting holes slightly to get it to fit. No biggie either. But then tried mounting it 2 different times and neither times could i get it to seal correctly. Both times were with new OEM gaskets. Tore it off, threw it on the desk and put the old one back on and went boating. Old one seals up great. Anyone else here have problems with one of these. I could have swore I read something here at one time but could find it in a search. Not that its a huge deal in the aspect of boating, but kinda hate looking at a 250 dollar SS paper weight on my work bench.

That comes from Sierra but years ago that SS housing was from Aqua Power inwhich Sierra bought out Aqua Power to not have competition around. Anyways with Sierra you have to watch some of their quality with products. Some are good and some are real bad.

The post you are talking about, I am thinking, is from SHunter, he had exactly the same problem. I am sure he will chine in.

Here:
https://www.offshoreonly.com/forums/...g-502-a-2.html

Sierra tech support is basically a one man band as that dude was talking about in his post. Their tech support really does not support retail end users. Dealers yes, boat owners not really,

Not trying to bash Sierra, but.................................... I had never had any problem with Sierra stuff, until I bought their SS tstat housing. Looks pretty, but it didn't fit for *&^$!! I have it in my junk pile right now. The bad part, many companies carry and sell this housing. I would bet that most, if not all don't know of the problems that consumers have had with this product. However, I was not surprised to hear from Sierra that they had never had a complaint about this housing. I haven't called yet, but soon, they will have at least one complaint.

By the way, I just replaced my water circulating pump and I struggled over whether to by a Sierra pump, which was about half of what a Merc OEM pump was. Then after this tstat housing fiasco, it was an easy choice. I will be very hard pressed to buy anything from Sierra that is used on a motor.

Perfect. Thanks SB. Thats the thread I was talking about. Looks as though my search skills are lacking.

Shunter....thanks for the info as well as everyone else. Never realized it was a Sierra part. I guess I'll give the company I ordered it from a shout and see what they have to say. Obviously it isn't gonna fit so hopefully they'll be understanding. Sounds like there is no point in calling Sierra since customer service is lacking. Thanks again OSO

One would have to ask where did you buy your SS Sierra housing from ? The reason I ask as with online shopping no warranty offered but if you bought from a Dealer whom is a Sierra dealer then a warranty could have been issued. And that would also be covered with warranty thru myself - thru Sierra.

Next question is your intake a stock OEM intake that Merc used for your app ?

You also have to machine ( cut down the divider ) the shorter housing flange makes it bottom out and won't seal, happened to me 502 mpi

Bought it from NuWave Marine. Talked to them about the problem and they suggested calling Sierra. I did talk to Sierra initially and they told me to go ahead and ream out the mount holes, which I did. Mounted it and it leaked. Replaced it with my old reconditioned OEM housing and re-installed it.

Yes, my intake is stock OEM.

I happened to read this post while I was talking to a/the Sierra tech guy today. I asked them about the warranty. They said that it is warranted whether a dealer or online seller sells the part. Problem is, most online sellers either don't know about the warranty or don't want to bother with it. As long as you have a copy of the receipt they will warranty the part. Normally, Sierra says it's easier to go back to the place you bought it from, but since I had talked to them in the past and they were aware of the situation, they are going to issue me a return label so I can send it back (along with a copy of my receipt from NuWave). They will notify NuWave Marine and the actual refund will come through NuWave. Anyway, kudos to Sierra for grabbing the bull by the horns and taking care of this issue.