This is where it gets interesting. I have many quibbles with engine suppliers and their 'official' designations. I did some research on this and have gross tallies and net tallies for teams if some suppliers are considered one and the same.
For the purposes of this question, Ford and Cosworth were treated as one. Their work together and badging was incredibly close. However...
Would you count Lotus across all of their incarnations?
Lotus died in 1994. But they did have nine gross engine suppliers; Climax (1958-1967), BRM (1966-1967), Ford (1967-1983, 1992-1993), Pratt & Whitney (1971), Renault (1983-1986), Honda (1987-1988), Judd (1989, 1991), Lamborghini (1990) and Mugen-Honda (1994).
Eight net if you consider Mugen-Honda and Honda to be the same.
Possibly Sauber or Arrows, but part of me hopes it is a really obscure answer. Like Mercedes Benz or Ferrari obscure!!!
Sauber have had four net engine suppliers; Mercedes-Benz (1993-1994), Ford (1995-1996) and Ferrari (1997-2005, 2010-).
Five gross if you count Ilmor (1993) as different to Mercedes-Benz (1994), considering it
was a Mercedes-Benz engine built by Ilmor but with an Ilmor badge in case the project flopped. All subsequent Mercedes-Benz F1 engines were also still Ilmors.
BMW Sauber was a BMW works team and different.
Arrows was the all-time best I found with ten gross suppliers; Ford (1978-1984, 1989-1990, 1991, 1994, 2002), BMW (1984-1986), Megatron (1987-1988), Porsche (1991), Mugen-Honda (1992-1993), Hart (1995-1996), Yamaha (1997), Arrows (1998-1999), Supertec (2000), Peugeot (2001)
But you could consider it nine net suppliers if Hart and Arrows' own engines are considered the same supplier; Arrows simply bought Brian Hart Engines Ltd. Even Megatron was to BMW what Supertec and Mecachrome were to Renault.
So for me it's Arrows 10 (9) to Lotus' 9 (8) and Pezzarinho's turn to ask.
I said which team not which constructor. And as noted above, the Lotuses of the 2010s aren't the same as that which died a death in 1994. "Lotus Pacific" my arse.